I don't think it's useful to categorize all of those posts twice for the purpose of consistency. It is worth mentioning, however, specific posts on my predecessor blog Chess for All Ages.
I'm sure I've overlooked a few posts and will add them as I discover them.
Assume that White does castle Queenside [...] If White then moves the Bishop on g1, the Queen on f1, the Knight on e1, and the 'castled Rook' on d1 off the back rank, can White now castle Kingside, as the King and Rook have not yet moved?
the same question applies to any start position (SP) with King on c1 and the h-side Rook on any square except d1. It can also apply to any SP with King on g1 and the a-side Rook on any square except f1.
I'm no expert on the rules of chess960 (not to mention the rules of traditional chess), so my first reaction to this sort of question is always, 'Let's see what the rules say'. In 2009, the rules of chess960 were incorporated into the FIDE Handbook, under Laws of Chess :: Appendices (section: 'F. Chess960 Rules'). There we find
F.3 Chess960 Castling Rules: a. Chess960 allows each player to castle once per game, a move by potentially both the king and rook in a single move. [...]
That's clear enough. Since a player can only 'castle once per game', it's not possible to castle Queenside, then Kingside, or vice versa. As they say, 'When all else fails, read the instructions!'
I'll have a few more posts on castling over the next several weeks.
I’ve never played this game myself, but many of my friends and students have taken part in the traditional Fischer-random tournaments in Mainz. Most of them liked the new game. They were very happy not to have to waste time preparing for the game, and it was interesting to test themselves and compete with their opponents in solving original tasks. That being the case, one can only welcome the continued hosting of such events, and hope there will eventually be more of them.
This and the following excerpts are from Part 2 of 'Polemic Thinking' (PDF). [Polemic - 'an aggressive attack on or refutation of the opinions or principles of another' (Merriam-Webster.com)] Note the curious phrase 'to waste time preparing for the game'.
But this can hardly mean that chess960 should be promoted as the designated successor to everyday chess. [...] The problems involved with such an enormous change in the rules should be examined from all sides and tested, with all aspects considered in order to find out whether there are drawbacks that might prove dangerous to the future of chess.
Agreed.
One of the main criteria of beauty (along with subtlety and originality) is the soundness, the correctness of the moves, of the individual ideas, or of entire games. And here is where I have some doubts about the future of chess960.
Doubts? What doubts?
In Fischer chess, where the majority of the pieces – if not all of them – are standing in unusual positions, we must deal with many new and unknown elements. As a result, a chessplayer has almost nothing to refer to in looking for a move; he’s playing “without line or compass.” I can assure you that even leading grandmasters play a weak game of chess960, full of both strategic and tactical errors. [...] So these games almost never show us any aesthetic value. If we remember how hard it can be to discover the secrets of a position even in traditional chess, where we can refer to many generations’ worth of experience, what I’m saying becomes logically obvious.
As proof that 'even leading grandmasters play a weak game of chess960', Dvoretsky gives two examples. The first is the same game I used in A Chess960 Catastrophe.
The level of play demonstrated here by grandmasters isn’t much different from (to take an example from traditional chess) the efforts, successful or unsuccessful, to exploit the weakness at f7 from the starting position, and deliver the "scholars mate". Of course we need to take into account the fact that in Mainz, the games were played in rapid chess; however, I suspect that, even under a classical time-control, the quality of play would not have risen very much. In the early days of chess, many such naïve games were played. As experience grew, so did the understanding of the principles of opening play; new schemes of battle appeared and were worked upon, and those that didn’t work out were tossed aside.
Naive games?
In chess960, there will be practically no accumulation of experience: there are too many opening positions, and too many differences between them. And thus, the concept of the opening phase will find itself frozen, for a long time, at a childhood level.
Childhood level?
Let me summarize, briefly: Playing Fischer-random is undoubtedly interesting (and probably even useful: overcoming routine, and developing an unfettered approach to the position). But studying played games is of no interest, because it’s almost impossible for anything creatively important to come from them (when measured against the level that both amateurs and experts in classical chess have grown accustomed to). So switching to this new game involves a serious risk that we may lose the aesthetic element of chess – and consequently, a great number of its adherents.
This argument is similar to the one I addressed in More Arguments Against Chess960, where I quoted Tim Krabbé writing, 'Any form of shuffle chess puts chess back 200 years.' This highbrow dismissal of chess960 because errors occur early ignores the reality of modern grandmaster chess. The start of a game is two players following a known path for 'X' number of moves, after which they follow computer based preparation for 'Y' number of moves, after which they are on their own. At this point there are three possible outcomes: either they agree to a draw, or one of them blunders, or they continue playing as best they can.
The example I used in that previous post was the first game from this year's Anand - Topalov match where Anand blundered on move 23. As we later learned, the blunder occurred because he forgot his preparation ('Y') and mixed up his ideas. As for agreeing to a draw as soon as move X+Y is reached, I could give lots of examples, starting with the 2004 Kramnik - Leko match, which saw a humiliating loss by Kramnik because his computer preparation was faulty.
The reason we see errors earlier in chess960 is not because the games are played at a 'childhood level' (Dvoretsky's phrase). It's because the players are on their own earlier. That they play chess better than they play chess960 is an illusion, a fiction, a fabrication due to conveniently overlooking the X+Y unoriginal moves that preceded real play. The truth is that GMs play chess960 very well.
As for Dvoretsky's remark that 'studying played [chess960] games is of no interest, because it’s almost impossible for anything creatively important to come from them', this implies that the only creative phase of a game is the opening. Is there really no creativity in the middlegame or endgame? If there isn't, I can throw away Dvoretsky's own books plus all the other books I've mistakenly acquired on those subjects.
As I wrote in the response to Krabbé, 'Playing over chess960 requires playing slowly from the very first move, just like playing a chess960 game requires real thinking from the very first move.' That last thought is worth repeating: chess960 requires real thinking from the very first move. Real thinking, creative thinking, has little to do with memorization. There is no 'X'; there is no 'Y'; there is only chess.
***
Later:See also 'The Chess Instructor 2009' (New In Chess 2008),Ch.2 'Mark Dvoretsky: Controversial Thoughts', section 'Should we all play chess960?' (p.30). On reading through this post a second time, I realized that Dvoretsky has selected a difficult chess960 position (RKR in the corner, where castling is particularly problematic) played at rapid time control and used it to condemn the entire idea of chess960. Anyone for sophistry?
At the end of 2007 and the beginning of 2008 on the ChessCafe site my big articles about the chess problems was published. It’s mainly about the very harmful influence of opening theory and some other aspects. Maybe somebody who wants to know my opinion about some important chess problems can read this article. I analyze the influence of opening theory, I analyze Fischerrandom/Chess960 and make another suggestion for how it’s possible to change the chess rules and so on. (From The big Dvoretsky interview, part 3).
Chessvibes also provided links to the ChessCafe articles, which were titled 'Polemic Thinking' -- Part 1 & Part 2 -- both PDFs. Here are the section headings from both parts.
1. The Components of Success; (à la Botvinnik) where the fourth component, 'Specialized chess preparation' is the springboard for the rest of the essay.
2. The Role of Opening Theory
3. The Principles of Working Effectively
4. Problems In Contemporary Chess; 'I could go on for a long time, making a list of the existing problems, but for now I would like to dwell on just one of them: the negative influence of opening theory on contemporary chess.'
5. Chess960
6. An Alternative Suggestion; (to chess960)
The flow of Dvoretsky's essay is evident from the headings. I'll look at the fifth section, on chess960, in another post. The sixth section, 'An Alternative Suggestion' is an attempt to decouple chess from the burden of opening preparation while keeping the familiar RNBQKBNR setup. I don't know if anyone has tried the idea in competition, but I'll leave the investigation to others who are more interested than I am.
To test my concern, I wrote a driver to call the generator thousands of times and to count the number of times each position was generated. Sure enough, the count for SP000 was approximately half of the count for the other SPs (Start Positions). After fixing the logical error, and feeling more confident about my Javascript skills, I decided to take a closer look at another generator I identified for my post on Chess960 Position Generators on the Web, i.e. the generator at very.co.il/services from a company called Very Ltd.
This second generator, based on the same die-rolling technique used by people to generate a chess960 position, was more sophisticated than the generator I had studied for the first cut. I adapted it to my needs, used my driver to verify its accuracy, and updated my page of Chess960 [Fischer Random Chess] Start Positions to use the adaptation. At the same time I incorporated a comment made to Another Generator to improve the presentation of my generator.
While doing the above, I realized that the IF/THEN table technique used to convert between SPs and their corresponding numbers ('If ID=SP000 then SP=BBQNNRKR' or vice versa) could be replaced by the method described in Calculate SP Numbers in Your Head. I'll do that in another programming project.
You have written about [Genrikh] Chepukaitis. Chip wasn't only an incredible blitz player, he was a real chess player. He didn't care what, where, why or how much, the main thing was to play. Chess has gradually lost this quality. Real players want to play, not to laboriously study and analyze openings at home. They can't do this, or they don't want to do it, it's boring for them. Perhaps I understand them better than you do, as I'm one of those types myself.
[Blitz is] a real game, a game in the literal sense of the word, and you're playing against a specific opponent, trying to exploit more than just their chess weaknesses. That's why I really like the idea of random chess, as this could take chess back to its original purpose as a game and you wouldn't have this monstrous opening preparation.
According to my page on the World Chess Championship, Index of women players, Levitina participated in six Women's Candidate events, once qualifying for a title match which she lost to Maia Chiburdanidze in 1984. For more about her, see the Wikipedia page, Irina Levitina.
After the comment about 'monstrous opening preparation', she added, 'But even if people start playing this kind of chess, it's still difficult for me to imagine myself ever sitting at the chess board again.' The Sosonko book doesn't mention when the essay was first published, except to say that it was in 'New in Chess' magazine. The phrase 'Smart Chip' in the book's title is a reference to Chepukaitis.
The main task was to investigate the source of the problem mentioned in Impediments to Chess960 Acceptance. Did I just happen to stumble on the only error in the original code or were there more? I extracted the ID/position equivalences, compared them to my database of SPs, and found a dozen discrepancies. The most obvious error was the assignment of SP000 (BBQNNRKR) to no.960, because the standard numbering scheme starts at 000 and ends at 959. As for the other errors, they were all incorrect ID/position equivalences scattered at random in the IF/THEN tables.
I replaced all the original equivalences with my own, made a few other changes, and added the position generator to my page of Chess960 Start Positions. On top of a working chess960 generator, I have a foundation for any related ideas that might come along.
While it's useful to know that you don't need technology to play chess960, it's also useful to rely on that technology when it's available. Generating a random chess960 start position is one obvious example where technology makes the process a lot easier; calculating the equivalent SP number is another. What tools are available on the web to accomplish these tasks? A search on 'chess960 position generator' appears to identify dozens.
The first on Google is the well known FISCHERANDOM CHESS: Random Position Generator at Chessgames.com. Along with a random start position, it returns a FEN string that can be used to create a PGN file to record the moves of a game starting from that position. Unfortunately, as I've mentioned several times, the 'position #' attached to the start position is nonstandard. This means you need a second tool to do the conversion.
A little further down the Google list is the Starting Position Generator at Chess-960.org. Once you discover its quirks (you have to click the 'generator' button before clicking the 'notation' button) it accomplishes the task it's billed to do. Unfortunately, as I pointed out in Impediments to Chess960 Acceptance, the tool has at least a couple of bugs, rendering it unreliable.
Another tool is the Chess 960: Starting Position Generator at Very.co.il. Unfortunately, like the Chessgames.com tool, it ignores the standard chess960 numbering scheme.
Along with these links, Google returns a variety of other tools for different platforms, including at least one calculator. It was hard to believe that nothing did the task I wanted, so I decided to adapt one of them to suit my needs. I'll cover that in another post.
e.g. to determine that the traditional start position RNBQKBNR is no.518 in chess960 numbering, or that no.534 represents RNBKQBNR (the traditional start position with King and Queen switched),
without using a printed table. Then, as so often happens, I got sidetracked with another issue, this time it was the problem of jargon. In this post, I'll get back on track with the numbering.
1) Start with the KRN sequence
The first thing to notice about chess960 numbering is that the start positions are grouped according to the sequence of Kings, Rooks, and Knights (KRN). For example, the first 96 positions (SP000 through SP095) all have those pieces in the sequence NNRKR, the next group of 96 positions have the sequence NRNKR, and so on. This implies that there are 10 different sequences of KRN, as shown in the following table.
0 NNRKR 000
1 NRNKR 096
2 NRKNR 192
3 NRKRN 288
4 RNNKR 384
5 RNKNR 480
6 RNKRN 576
7 RKNNR 672
8 RKNRN 768
9 RKRNN 864
Although I've given the complete table, I could have derived it with the help of a description. The table starts with the Knights in the first two positions, NNRKR. Each subsequent entry shifts the rightmost Knight one more step to the right. When the right Knight reaches the end, the left Knight shifts one step to the right and the right Knight joins it on its right side. Right? Right!
It's also worth noting that with the left Knight in the first position, the other Knight has four possible positions. With the left Knight in the second position, the other Knight has three positions, and so on -- four, three, two, one. It adds up to ten just like the pins in a bowling alley.
The numbers in that table are for convenience. The left column is a sequence number, while the right column is that sequence number multiplied by 96, the start position of that particular KRN group. [If you have trouble calculating 96 times 5 in your head, remember that 96 is equal to 100 minus 4, so 96 * 5 = (100 - 4) * 5 = 500 - 20 = 480.]
2) Account for the Q
The second thing to notice is that within each group of 96 positions the Queen shifts through the KRN sequence from left to right, one step at a time. This is shown in the following table, where 'xxxxx' stands for one particular KRN sequence.
0 Qxxxxx 00
1 xQxxxx 16
2 xxQxxx 32
3 xxxQxx 48
4 xxxxQx 64
5 xxxxxQ 80
Since there are six possible positions for the Queen and 96 positions in a KRN group, there are 16 different positions with a specific sequence of KRN&Q. Putting this together means that the first 16 of the 960 positions (SP000-SP015) all have the sequence QNNRKR, the second 16 have the sequence NQNRKR (SP016-SP031), and so on.
3) Finish with the Bs
Now the only pieces missing from the start position are the Bishops. Since one Bishop starts on a light square and the other on a dark square, there is no duplication and we have 4 x 4 = 16 unique positions of the Bishops. The sequence is shown on the following table.
00 BBxxxxxx
01 BxxBxxxx
02 BxxxxBxx
03 BxxxxxxB
[...]
15 xxxxxxBB
The Bishop table could also be derived from a verbal description. The Bishops start on a1 and b1 (or a8 and b8 for Black). Then the light-squared Bishop shifts to d1, f1, and h1. When the light-squared Bishop reaches h1, the dark squared Bishop shifts to the next dark square on the right, while the light-squared Bishop jumps back to b1, then d1, etc. Combining the Bishop table with the 16 different positions having a specific sequence of KRN&Q gives 16 unique chess960 positions, all pieces present and accounted for.
4) Put it all together
Taking the first chess960 position (SP000) as an example, it is represented by the pieces BBQNNRKR. Its KRN sequence is 'NNRKR', placing it in the first group of 96 positions (SP000-SP095); the Queen is in the sequence 'Qxxxxx', placing it in the first group of 16 positions (SP000-SP015); and the Bishops are in the formation 'BBxxxxxx', placing it first overall (SP000). A similar analysis shows why the position RKRNNQBB is numbered as the last of the 960 positions, SP959.
We can also see why the traditional start position (SP518 RNBQKBNR) and its twin (SP534 RNBKQBNR) are exactly 16 numbers apart. They both share the same KRN sequence, 'RNKNR', and have the same formation of Bishops, xxBxxBxx. Only the start position of the Queen is different -- RNQKNR (xxQxxx) vs. RNKQNR (xxxQxx) -- placing them in adjacent groups of 16 positions.
***
Here's a practical test. I've noted in the past that the Random Position Generator on Chessgames.com doesn't use the standard chess960 numbering system. It uses instead some proprietary scheme concocted by its software developer. I just accessed the page and it gave me 'position #334' as RQBBKRNN. What would the standard equivalents be?
First, let's take RQBBKRNN. Its KRN sequence is RKRNN, placing it in the last group of 96 positions, starting at SP864. Its Queen position is xQxxxx, placing it in the second group of 16 positions after SP864 (relative positions 16-31). Its Bishops are in the formation xxBBxxxx, making it the sixth position in the group of 16 (relative position 5). Adding these numbers together gives 864 + 16 + 5 = 885, which is indeed the SP number for RQBBKRNN.
Second, let's take 'position #334'? What does that represent in the standard numbering scheme? Dividing 334 by 96 and discarding the remainder gives 3, which places it in the group of 96 positions starting 288, i.e. NRKRN. Subtracting 288 from 334 gives 46; dividing this by 16 and discarding gives 2, which works out to xxQxxx. Subtracting 32 from 46 gives 14, which is the second to last of the Bishop formations, or xxxxxBBx. Combining NRKRN with xxQxxx gives NRQKRN; combining that with xxxxxBBx gives NRQKRBBN. A table lookup confirms that SP334 is indeed the number for position NRQKRBBN.
***
The title of this post is 'Calculate SP Numbers in Your Head'. Whether or not you can really do this depends on how agile you are with mental arithmetic. I find it helps to jot down the intermediate results -- 864, 16, and 5, as in the first example -- before combining them. The upshot is that if some day you are stranded on a desert island, you will be able to calculate chess960 SP numbers without having a reference table. As helpful as that might be, I suspect that you will have more important things to do on that island than play chess960.
I've already demonstrated that a chess960 start position (I'll call it 'SP' for the rest of this post) can be generated without any technology -- see Some Arguments Against Chess960 for the details -- so why should determining the SP number be more complicated? I had already worked out part of a promising method, but was stuck on one point when, as a followup to How *NOT* to Play Chess960, I checked the origin of the term 'array':-
'[Howcast.com video] 0:29 - Step 1: Learn Chess960 terms. "Array" is the initial arrangement of pieces on a board.' • Who says "array"?
There are enough obstacles to promoting chess960 without introducing unnecessary jargon into the explanation. The term 'start position' means the same as 'array' and is immediately understood without defining it.
A search on 'chess960 array' returned my 'How *NOT* to Play' post at position no.3 (proof that the term 'array' is not widely used), the Howcast.com video that was the object of scorn in that post at no.2, and (drum roll...) a Wikipedia page at no.1: Chess960 numbering scheme. This was the source I had expected to find. Wikipedians have done a terrific job of documenting the complete range of human experience, but sometimes they go too far.
The Wikipedia page gave two complicated algorithms to go from SPs to their numbers and vice versa, and it would be impossible to follow the algorithms without referring to the page. I was looking for a method that could be used on a desert island. While that page wasn't the answer, it did provide a helpful clue that solved the point I had missed in searching for a promising method. I'll give that method in another post.
At position no.4 in the search results was a post from Rybkaforum.net, Kasparov on Chess960, etc., which used the term 'array' in a different context:-
[Kasparov] suggests choosing a subset of Fischer Random that would include only natural positions. I have tried to promote a similar idea where, for instance, 25 positions can be selected from the chess960 array
This apparently uses 'array' to mean the complete set of all 960 legal SPs, as opposed to a single SP. Since there is no generally accepted term for this -- I just used the mathematical word 'set' to mean the same thing, but I could have used 'catalog' -- the word 'array' is as good as any.
The Rybkaforum.net post wades into the jargon swamp a bit later when it uses the term 'orthochess' to mean traditional chess. This is another concept that really needs a generally accepted term. I'm in the habit of writing 'SP518 RNBQKBNR' to keep the meaning precise, but I'm sure that very few chess players would understand that shorthand out of context, making it jargon at its worst.
***
(*) My own table is here: Chess960 [Fischer Random Chess] Start Positions.
How many mistakes can you make in a video that runs less than two minutes?
A few weeks ago I used another Howcast video in How To Use Rybka?!. How many mistakes are in that clip?
Two of my own resources occupy two positions in a list of top-25 resources for chess960. Where are Chess.com and Schemingmind.com?
I used Yusupov's work in a recent post on opening theory -- Yusupov's 'General Principles of Opening Play' -- making it appropriate to examine his thinking about chess960. Lektion 1 (Lesson 1) is titled 'Unprotected Pawns / Weak Points' and starts with the same small table I gave in Undefended Pawns in Chess960 Start Positions, showing the number of start positions with specific counts of undefended Pawns. This is followed by an example game, Bacrot - Lanka, from the 2005 FiNet Open at Chess Classic Mainz (CCM5). The start position is shown in the following diagram.
SP829 RKNBQRBN
Here are Yusupov's comments on the first few moves. (I used Google Translate for a basic translation, then cleaned it up based on my own limited understanding of German. It's still a rough translation, but the meaning comes through.)
If we look closer at this start position, we see that the Pg2 and of course its counterpart on g7 are unprotected. These Pawns [Google: 'farmers' (!)] are currently considered weak. Of course, it is not necessary to defend them immediately, but you should not forget them!
1.e4 c5? - 1...e5 would have been better, but Lanka gladly plays the Sicilian defense in traditional chess, and can not resist to achieve this structure here. His reflex move leads to big difficulties.
2.f3! - White now attacks the Pawn on c5 with the Bg1 and at the same time opens the diagonal e1-h4 for his Queen.
2...Bb6? - Overlooks the second and far more serious threat. After the better 2...d6 follows also 3.Qg3 Ng6 4.Bxc5, and if 4...Qb5, White can protect both attacked pieces: 5.Nd3, and it is very questionable whether Black can demonstrate enough compensation for the Pawn.
3.Qg3+ - Wins neatly the Pg7.
Here GM Yusupov ends his analysis of the game. The second example in the lesson is an analysis of the complete game Shirov - Naiditsch from the same event. It starts with SP897 BRKBQRNN, one of four start positions with three undefended Pawns at the beginning.
The first lesson is followed by 39 more lessons. The complete course of 40 lessons is just one of eight courses, ranging from beginner to expert level. Is there a better exposition of chess960 available in any language?
I've written about Chess Tigers before -- use the search box in the right sidebar to find specific posts -- and even if you've never heard about them, you've certainly heard about their annual event Chess Classic Mainz (CCM), where one of the regular participants is World Champion Anand. The lessons date from 2004, and using the explanation at the top of the page, 'Jeder der unten angegebenen Kurse besteht aus 40 Lektionen...' (Google Translate : 'Each of the following courses consists of 40 lessons ...'), we learn that the materials available here are just samples ('Inhalt, Lektion 1, Lektion 2' = 'Content, Lesson 1, Lesson 2').
Some of the lessons are classified by IPS (e.g. 'IPS 1800' for 2004), which is defined in the lessons as 'Individual Player Strength', and which undoubtedly corresponds to the Elo ratings of traditional chess. I poked around the sample lessons, liked what I saw, and will present a snippet in my next post.
Chess960 is an evolution of traditional chess. To use an analogy, imagine I build a house on a lot that was previously empty. I call the road it is on 'Chess Street'. The house might be in use for centuries before someone (a certain Mr. Fischer) gets the idea to build more houses on the same lot. He builds 959 similar houses and, to make it easier to identify the houses, assigns them numbers. My original house turns out to be no.518 on Chess Street. Note that I haven't altered the function of the original house nor have I destroyed it. It is still available to everyone who used it before. But for those who are tired of the same house and want something a little different, they have many choices.
I could carry the analogy further, but I'm not sure it would help clarify the difference between traditional chess and chess960. People who want to continue living at no.518 on Chess St. can do so. They do, however, have choices that were not available 20 years ago.
In another forum on Chess.com, I used an anology -- Chess Island -- that I call the 'beach analogy'.
Chess960 is like a tropic island having 960 gorgeous beaches all with white sand and blue water. For some obscure reason, probably to do with herd mentality, everyone who vacations on the island chooses the same beach, no.518 in the numbering scheme assigned by the pioneer who first charted the island. There are so many people on that particular beach that there is no place to throw your towel down or pitch your beach umbrella, unless you cling to the rocky, dangerous cliffs that line both sides of the beach. If you want to go swimming or snorkeling you have to go out hundreds of meters to get away from the crowds. Of course, you can always rent one of those robot boats that ferry the thrill seekers as far out as possible, but the real insiders say that the increasing use of those boats is rapidly destroying the beauty of the beach.
Meanwhile the other 959 beaches remain just as they were when first discovered. A few intrepid vacationers prefer those beaches to no.518, although they have a hard time explaining why. Maybe they don't like crowds and just want to get away from it all. Whatever the reason, on every vacation they choose a different beach at random and enjoy themselves so much that they are reminded why they came to the island the first time. Once in a while they go back to the crowds at no.518 to renew old friendships and revisit old haunts, but it is never the same as it was before.
I'm sure there are other analogies.
From: Could we please stop calling Chess960 a variant?.
SP534 (RNBKQBNR) has the same characteristics as SP518 (RNBQKBNR). Only the castling considerations are different, but that's enough to make it theoretically separate. - Mark [2nd October 2010, 12:07am]
Until computers came along, when good old chess, weakened at the knees, started to stumble under the burden. I agree with the person who called chess960 a mutation. It's fortified chess, made to withstand the onslaught of the chess playing engines. It's an evolution of modern chess which was itself an evolution of medieval chess 500 years ago. Times change and things change with the times. - Mark [2nd October 2010, 11:10pm]
The history of shuffle chess goes back hundreds of years. Gligoric, in his book on chess960/FRC, dates the idea to 1792 and gives games from 1842 and 1851. The 1851 game has the Bishops for each side starting on the same color squares, which is not done in the better evolutions of shuffle chess.
Fischer added two important concepts to the earlier forms of shuffle chess. First, he specified that the King must start between the Rooks. Second, he defined castling to have the King & Rook end up on the same squares as in traditional chess (RNBQKBNR), for both O-O-O and O-O. That's what makes traditional chess a subset of chess960 and what gives the other 959 chess960 start positions the same feel (and appeal) of traditional chess.
Comparing chess960 to earlier forms of shuffle chess is like comparing the Wright brothers' invention to hot air balloons. They are not the same thing. - Mark [5th October 2010, 01:06am]
Without the two rules that you mention, traditional chess (aka modern chess) would not be the game that we play today. It would be some other game. So, yes, traditional chess *was* invented by the people who introduced the rules for castling and en passant. That's not to say that they invented the precursors of traditional chess, like medieval chess or like the versions without castling and en passant. The evolutionary sequence is clear and undisputable.
My point is that chess960 incorporates traditional chess 100%. When you play traditional chess, you are in fact playing chess960, restricted to one of the 960 different start positions (RNBQKBNR). I could say that the just-finished Olympiad was really a chess960 tournament restricted to RNBQKBNR, and I would not be wrong. (I would raise a storm of controversy, but I would not be wrong).
Chess960 is an evolution of traditional chess. To use an analogy, imagine I build a house on a lot that was previously empty. I call the road it is on 'Chess Street'. The house might be in use for centuries before someone (a certain Mr. Fischer) gets the idea to build more houses on the same lot. He builds 959 similar houses and, to make it easier to identify the houses, assigns them numbers. My original house turns out to be no.518 on Chess Street. Note that I haven't altered the function of the original house nor have I destroyed it. It is still available to everyone who used it before. But for those who are tired of the same house and want something a little different, they have many choices.
I could carry the analogy further, but I'm not sure it would help clarify the difference between traditional chess and chess960. People who want to continue living at no.518 on Chess St. can do so. They do, however, have choices that were not available 20 years ago. - Mark [5th October 2010, 11:43pm]
For one thing, chess is de facto a simpler game than chess960. The fixed start position in chess means that players can prepare by compiling databases, studying books, running engines on positions they will encounter in real play, and memorizing opening variations. In chess960, those crutches are no longer available.
Traditional chess also limits the number of recurring patterns that can arise early in the game. This makes it easier to master certain Pawn structures, like IQPs or Pawn chains anchored on e5. In chess960 you have to work out unfamiliar patterns while the clock is ticking. Of course, once you reach the endgame, you are back on familiar territory. This gives an advantage to good endgame players, who are a rare breed.
Some players report a light feeling of nausea when they start to play chess960 and are confronted with a new start position. I'm convinced this is because they actually have to think starting from the first move, and this unfamiliar feeling literally sets their thoughts spinning. It's like the panic you feel in traditional chess when your opponent makes a move you didn't expect.
One day, traditional chess might even be considered the equivalent of training wheels for chess960. After you have mastered the basics of RNBQKBNR and are ready for a fight starting from the first move, you move to random start positions. - Mark [7th October 2010, 02:26am]
The chess960 castling rules are based on traditional chess rules. It is exactly those rules (1) that make traditional chess a subset of chess960 and, (2) that drive the other 959 chess960 start positions toward middlegame positions that look like they arose from traditional chess. It is another example of Fischer's genius for all things concerning chess. - Mark [9th October 2010, 11:52pm]
You're right that 'half of the positions are reflections of the other half', but, as glider pointed out, they don't play the same because of the castling rules. Let's look at an example.
In traditional chess (SP518 RNBQKBNR) there are variations that allow castling O-O in four moves, which is the minimum. One example is the Ruy Lopez, Berlin Defense: 1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O. After castling, the castled pieces are on f1 and g1. This can lead to the Berlin Wall variation that helped Kramnik win the World Championship from Kasparov in 2000.
Now let's take the reflection, which has the King and Queen switched (SP534 RNBKQBNR). The equivalent variation is 1.d4 d5 2.Nc3 Nf6 3.Bg5 Nc6 4.O-O-O. This time the castled pieces are on d1 and c1. It's not at all the same thing. Now the Berlin Wall doesn't work, because the d-Pawn is protected. The theory is completely new.
Two positions that are reflections of each other I call 'twins'. I've also seen them called 'mirrors'. Whatever you call them, they are different positions that lead to different variations. - Mark [11th October 2010, 01:07am]
From: Please, can we make white have to think for once?
So if I play a game of traditional chess, it's an 'all-information game'. If I then play a game of chess960 with start position RNBQKBNR (SP518), which uses *exactly* the same rules as traditional chess, it's not an 'all-information game'. It appears that you've confused information available before the game with information available during the game. - Mark [11th October 2010, 10:41pm]
Random conditions? Before a casual game you don't know what color you will play. Haven't you ever hidden a White Pawn in one hand and a Black Pawn in the other and asked your opponent to choose? That selection is a random process. Before a tournament game, you don't know who your opponent will be until the pairings are announced. The pairings are determined by a third party and there are always random factors involved.
There is more hidden information in a traditional chess game than there is in chess960. In traditional chess you often have no idea how much your opponent knows about the particular opening you are playing. He might have played it dozens of times and analyzed it into the endgame. In chess960 you know that both players are playing without preparation. - Mark [14th October 2010, 01:12am]
The idea is so new that it's a novelty for everyone, but I accept your point. I also wonder whether it's more interesting for experienced players than for beginning chess players. Time will tell.
As for how experienced you need to be to appreciate it, I think most class A players (rating 1800+) know that opening preparation goes a long way to getting a good game. It would be interesting to conduct a poll asking 'When you study chess, what percent of your time do you spend on A) the opening, B) the middlegame, C) the endgame, D) Other [history, for example]', then correlate the responses according to rating. I wouldn't be surprised to find average club players and below (<1500) spending a lot of time on openings.
What got me hooked on chess960 was being forced to think about the game starting with the first move. It's not at all the same as reeling off the first 10 moves of a Closed Lopez (or Poison Pawn Najdorf, or King's Indian Bayonet Attack, or ..., or ..., or ...) from force of habit, then relying on preparation for the next few moves, then really starting to think creatively somewhere around move 15. With chess960, the creative thinking starts when you see the initial position. You don't have to be a GM to enjoy that. Isn't the intellectual challenge one of the reasons we play chess? - Mark [14th October 2010, 01:44am]
To summarize these arguments against chess960: traditional chess uses the only logical start position; it has survived 500 years without change; Fischer didn't invent chess960; it's really a different game; the rules of castling are different; it should be called chess480; it introduces uncertainty; only top GMs will be interested in it. I'm sure there are more...
With many people wondering about the future of chess after the IBM computer Big Blue beat Garry Kasparov earlier this year, Fischer's statement that computers would be at a considerable disadvantage in Fischerandom Chess received a great deal of attention. He stated that without access to databases of the millions of opening variations in traditional chess, computers do not really play chess all that well.
As an aside, don't read too much into the sentence that 'IBM computer Big Blue beat Garry Kasparov earlier this year'. The press conference took place in June 1996, so the Kasparov - IBM match would have been the first, played in February 1996. Kasparov suffered his only loss in the first game, but won the match by winning the last two games. It wasn't until the following year that Deep Blue beat Kasparov in a match (see a page on my World Championship site, Kasparov vs. IBM's Deep Blue, for a few details about the two matches).
Fischer's thoughts on computers drew attention from the experts. In The birth of Fischer Random Chess by Eric van Reem, which first appeared in 2001, the well known chess journalist wrote,
Fischer stated, that without access to databases of the millions of opening variations in traditional chess, computers do not really play chess all that well. However, Matthias Wüllenweber, one of the founders of ChessBase, has a completely dífferent opinion on that subject. Last year, when "Fritz on Primergy" played two Shuffle Chess games against German number 1 Artur Jusupov [Yusupov], the software specialist said: "When playing F.R Chess unusual patterns come up on the board. Knowledge of these patterns, however, is one of the main weapons for humans in their battle against computers.
Wüllenweber refers to a test his partner Frederic Friedel did with Hungarian Grandmaster Andras Adorjan. Friedel showed Adorjan several positions for a period of ten seconds. The Hungarian could recall those "normal" postions far better than amateur players did. Humans remember so-called "chunks" e.g. they do not remember pawn on f2, g2 and h2, King on g1 and Rook on f1, they remember the chunk "Castling Kingside".
If you build up a position without those patterns, but try to put up a position that really doesn´t make sense, with pawns on the first and eigth rank for example, there is hardly any difference in memorization between amateurs and grandmasters. According to Wüllenweber this 'thinking in chunks' is the main difference between humans and computers and the difference in ELO is some hundreds of points. A computer can play with 3 knights or 5 rooks, no problem.
This last point is in accordance with a sentiment I reported in A Few Novel Ideas (with links to the ICCF.com forum for the context of the discussion).
"For serious correspondence chess, as opposed to casual correspondence chess, playing chess960 games is a step in the WRONG direction. The reason is simple : the human knowledge effect in the games will be further reduced since the engines that are already affecting classic correspondence chess have zero problems adapting to chess960."
So who is right, Fischer or his critics? Since Fischer's heyday occurred when computer chess was still in its infancy (the first World Championship for Computer Chess took place in 1974), it's easy to conclude that the experts who came later were far more knowledgeable. Fischer, however, surprised us many times in the past and he might well surprise us in the future, long after his death.
The area of interest I have is in Advanced Chess960 (computer assisted). I want Chess.com to recognize this way of playing by allocating it a rating's category. If you want to read up on Advanced Chess, type it into Wiki. If you type in Advanced Chess960 however, you only get a couple of links. It is early days. [...]
Why would I want to have computer assisted Chess960 play accepted at Chess.com? That question is actually quite simply answered with an analogy. The computer is like a telescope that can help to peer deeper into the Chess960 galaxy than can be seen with the naked eye of our own intellect. Why not use a computer then?
Responses to the question, 'Why not use a computer?', came quickly.
Kacparov: 'Advanced chess is cheating here, if you want to play it you need to go somewhere else, sorry.' • Atos: 'It's not allowed to use assistance in rated games, even if both sides agree.'
Right question, wrong forum. Chess.com members have the same tolerance for accused computer cheaters that the Holy Office of the Inquisition had for those poor souls suspected to have strayed from Catholic orthodoxy. A recent case involving IM (and WGM) Yelena Dembo was discussed on The chess games of Yelena Dembo at Chessgames.com. In the online world, tongues will wag and you're guilty until proven innocent. Good luck with that.
Not one to give up easily, glider1001 set up his own group on Chess.com: Advanced Chess960 Community, complete with its own forum, Advanced Chess960 Community - Forums. While member numbers are low, and likely to remain so, there are already a screenful of interesting chess960 topics, penned by glider himself, on the forum. Many of these are more about chess960 opening theory than about computer assistance. I hope glider doesn't mind if I rely on some of his ideas, duly attributed, for future posts on this blog.
I discussed the format of the SchemingMind dropout tournaments in Pyramids and Dropouts. The current game was played in the last round of the 2009 event, where all four surviving players were on the verge of elimination. A loss in either of the two last round games would be curtains for that player. In this current game a draw for White would also mean instant elimination, while Black needed a win here and a draw in the other game, or vice versa. The bottom line was that both players were in a situation to play for a win.
The following diagram shows the game with Black to play his fourth move. The start position (SP880 BBRQKRNN), still visible in the diagram, has a curious symmetry. The royalty, located on the same center squares as in traditional chess, is flanked by the Rooks on the c- and f-files. The Bishops are on adjacent files, meaning also adjacent diagonals, on the Queenside, while the Knights are on adjacent files on the Kingside. The g- and h-Pawns are unprotected and subject to immediate attack by the Bishops. Castling O-O-O, to keep the King out of range of the opponent's Bishops, looks better than O-O.
During the first few moves, both players have been preoccupied with the safety of the Kingside Pawns, at the same time following a policy of development coupled with attention to the center. White has just played 4.Nhg3. Black could have continued similarly with 4...Ng6, but instead went into complications with 4...h5, threatening the enemy Knight. Unlike the game in the 'Seeds of Victory' post, which opened with strategical maneuvering by both players, the current game veered into tactical calculations, based on mutual shots against the Knights.
After a few more moves the game reached the position shown in the second diagram, where White has just castled O-O-O. It's hard to say who stands better. The swap of a center Pawn for the h-Pawn probably favors Black, but this sort of positional reckoning takes a back seat when tactical complications abound. The attacks on the Knights continued with 11...f5 12.f4, and Black eventually prevailed. Here again is the complete game score, courtesy of SchemingMind.
[Event "2009 Chess960 Dropout Tournament"]
[Site "SchemingMind.com"]
[Date "2010.07.29"]
[Round "6"]
[White "thebirdolux"]
[Black "wilfried"]
[Result "0-1"]
[Variant "fischerandom"]
[SetUp "1"]
[FEN "bbrqkrnn/pppppppp/8/8/8/8/PPPPPPPP/BBRQKRNN w KQkq - 0 1"]
1.c4 Nf6 2.e4 c5 3.Ne2 e6 4.Nhg3 h5 5.b3 h4 6.e5 Ng4 7.Ne4 h3 8.Nf4 Nxe5 9.Nxh3 Qh4 10.Qe2 b6 11.O-O-O f5 12.f4 Qg4 13.Rfe1 Qxe2 14.Rxe2 Nc6 15.Bxg7 fxe4 16.Bxf8 Nd4 17.Re3 Kxf8 18.Bxe4 Bxe4 19.Rxe4 Ke7 20.Rh1 Nf7 21.g3 b5 22.d3 Rh8 23.Nf2 Bc7 24.Ree1 Ba5 25.Ref1 Nd6 26.cxb5 N6xb5 27.Ne4 d5 28.Ng5 Ne2+ 0-1
Once again, it's not immediately clear why White resigned in the final position. White has a Rook and two Pawns for a Bishop and a Knight, but Black's minor pieces are swarming around White's King. I imagine that a detailed analysis would show imminent material loss for White.
SP783 presents a couple of awkward challenges. First, the Queens are in a corner facing a Bishop at the other end of the long diagonal. On top of that, castling O-O-O looks to be more likely than O-O, but the King on the a-side will be under pressure from the enemy Bishops sitting on adjacent diagonals. How did the game proceed?
The second diagram shows the position after ten moves have been played by each side. Using the techniques that I introduced in Count the Developing Moves and Move Order in the Opening, let's summarize the development thus far.
White has made four Pawn moves, Black six (the a-Pawn has moved twice). Both players have castled O-O-O as expected. Of his remaining five moves, White has made three with the Knights to take control of d5, and two with the Queen to transfer it to c2. Of his remaining three moves, Black has taken two to get the Knights off the back rank and one to move the King to b8.Neither player has moved a Bishop, but all four are already playing an active role in the game; moving the f- and g-Pawns was sufficient to activate them. Except for castling, neither player has moved a Rook, but all four are developed on central files, waiting for lines to open.
All things considered, White's position makes a better impression. The Queen and Knights are more active, while the d2-d4 break is a bigger threat than Black's pushing the a-Pawn. Although White went on to win, it would take a more profound analysis to determine if the seeds of victory were already present in the diagrammed position. Here is the complete game score, courtesy of SchemingMind.
[Event "2009 Chess960 Dropout Tournament"]
[Site "SchemingMind.com"]
[Date "2009.07.02"]
[Round "3"]
[White "Tyler"]
[Black "wilfried"]
[Result "1-0"]
[Variant "fischerandom"]
[SetUp "1"]
[FEN "qrknrnbb/pppppppp/8/8/8/8/PPPPPPPP/QRKNRNBB w KQkq - 0 1"]
1.f4 g6 2.e4 Nc6 3.Nde3 O-O-O 4.O-O-O d6 5.g3 Kb8 6.c3 e5 7.Nd5 f6 8.Nfe3 Nd7 9.Qb1 a5 10.Qc2 a4 11. Kb1 Ne7 12.Nxe7 Rxe7 13.d4 Qa5 14.fxe5 fxe5 15.d5 Nb6 16.b4 axb3 17.axb3 c6 18.c4 Bg7 19.Re2 Kc7 20.Qa2 Qxa2+ 21.Rxa2 Nc8 22.Kc2 h5 23.b4 Red7 24. Bg2 Bh6 25.Bh3 Rh7 26.Ra8 h4 27.Bg4 hxg3 28.hxg3 Nb6 29.Rxd8 Kxd8 30.c5 1-0
I'm not sure why Black resigned, but he must have been looking at material loss and had too much respect for his opponent's endgame skill to continue.
It is perhaps not generally realized that opening theory in chess proceeds on certain definite assumptions. They are simple enough and once learned will never be forgotten. They are:
- In the initial position White, because of the extra move, has a slight advantage. Consequently:
- White's problem in the opening is to secure the better position, while
- Black's problem is to secure equality.
The elaboration of these questions in each individual case is what is meant by 'the theory of the openings'.
Although we don't know for sure, it is highly likely that those three 'definite assumptions' apply to the other 959 chess960 start positions. A few paragraphs later Fine continues,
There are two fundamental concepts in the opening : development and the center. Development is getting the pieces out. The center consists of the four squares in the geometrical center of the board. The basic principle is that it is essential in the opening to develop all the pieces harmoniously and in such a way as to secure the most favorable position possible in the center.
More elaborately, there are ten practical rules which are usually worth sticking to, though the expert player will be aware of the many exceptions. These rules are:
- Open with either the e- or the d-Pawn.
- Wherever possible, make a good developing move which threatens something.
- Develop Knights before Bishops.
- Pick the most suitable square for a piece and develop it there once and for all.
- Make one or two Pawn moves in the opening, not more.
- Do not bring your Queen out too early.
- Castle as soon as possible, preferably on the King's side.
- Play to get control of the center.
- Always try to maintain at least one Pawn in the center.
- Do not sacrifice without a clear and adequate reason.
[Followed by four reasons for a Pawn sacrifice]
Note the mention of harmonious development in the first paragraph of the quote. A frequent criticism of chess960 is that many of the start positions lack the harmony found in the traditional position (SP518 RNBQKBNR). While this is certainly true, it is also true that an unskilled player will often ruin the natural harmony of SP518 by developing the pieces unharmoniously, thereby turning gold into rubbish. In contrast, the skilled chess960 player is often faced with the challenge of turning rubbish (speaking figuratively; I've never met a chess960 start position I didn't like) into gold. Since both players are faced with the same start position, the skilled player will achieve harmony of the pieces faster than the unskilled opponent.
As for the 'ten practical rules', there is some overlap with Yusupov's principles plus many new ones. Again there are guidelines particular to the RNBQKBNR setup mixed with more general guidelines. Specifically, the cautions on the minor pieces and on the Queen sortie apply to SP518; the cautions on the center Pawns and on castling Kingside probably apply to many start positions, although not all; while the other cautions undoubtedly apply to all chess960 start positions.
I'm starting to assemble a good collection of opening principles and, in future posts, will look at what other GM-level writers have to say on the subject. Then I'll return to the distinction between general chess960 principles and those that apply to SP518.
Do the opening principles in traditional chess (SP518 RNBQKBNR) apply to the other 959 positions?
An answer to this question requires some agreement on what is meant by 'the opening principles in traditional chess'. In Dvoretsky & Yusupov's book 'Opening Preparation', the first chapter 'General Principles of Opening Play' was written by GM Yusupov, a world class player who has dabbled in chess960. He opens the chapter with a question -- 'Let us ask what constitutes the strategy of the opening struggle in chess' -- then hones in on the following points.
These points are easily applied to all of the chess960 start positions. I would have liked to see a point about King safety, but maybe GMs assume this is obvious. Yusupov then adds a further point on 'opening structure'. The first time I read this I thought he was talking about Pawn structure, but I now think his meaning is broader.
He then refines the foregoing points, all of them very general, with 'Some simple rules'. (That is Yusupov's term; I would prefer to call them 'guidelines', since the 'rules of chess' are usually used to specify how the pieces move, the definition of checkmate, and that sort of thing.) His rules are:-
Here the general application to chess960 becomes less obvious. The point about Rook Pawns (a- & h-Pawns) is specific to the SP518 setup, where the Bishops often attack (and pin) the enemy Knights. The early development of the Queen might also be more important to SP518 than to other start positions. There are some chess960 positions where an early sortie of the Queen is needed to prepare the smooth development of the minor pieces, which in turn prepares castling.
These differences raises another question: Can the 'rules' that are specific to SP518 be generalized to apply to all start positions? I'll come back to that after examining 'opening principles' formulated by other top players.
The first point will remain open until someone discovers an example which is not fair to both players; to date, there are no known examples. The second point requres a survey of opening principles in traditional chess. I'll start that in the next post.
Other than these flawed approaches, what factors can guide the player who is facing a brand new chess960 start position? Are there hidden principles of chess960 openings waiting to be discovered by some future genius, the Steinitz of chess960? We may never know, but I thought it would be a good idea to collect a few ideas that I've introduced in previous posts on this blog and to take them to the next level.
In future posts I'll combine those ideas with known general principles in opening a traditional chess game.
A list of the book's contents on the Schachversand Niggemann page, Shall we play Fischerandom Chess?, tells us that the book is divided into three sections: a brief history of chess, the development of Fischer's idea, and sample GM games. Despite having been written and published in 2002, when there was little practical experience with the game that would later be called chess960 (when was it so named?), Gligoric's work still offers the best material on the subject.
Why did Gligoric write the book? He explains in the 'Author's Note'.
It was my pleasure to witness part of the process of creation of the randomized chess game, invented and formulated by the world chess champion [Bobby Fischer], who, having probably liked my interpretation of his match versus Spassky in my earlier book on Reykjavik 1972, at the time suggested the idea that I try to write a book myself about the unknown subject of this new version of the game of chess.
Like chess960 itself, the book has been largely ignored by the mass of the chess playing public. There are, however, a few reviews available on the web. Amazon.com currently has three Customer Reviews. One of these, by Gene Milener, author of one of the few other books on chess960, is another list of the contents. A second is more of an opinion on chess960 ('Fischerandom chess is unlikely to replace "classical" chess for much the same reason that the aluminum bats have not entered professional baseball: it would take a beautifully crafted game with a long tradition ... and throw it all out the window.') than on Gligoric's book. The third is unintelligible ('very useful for those who think clasical chess in diing into uncatchible theory+computer combo').
Of the reviews found on chess sites, the first chronologically is on Chessville.com (2002): Reviewed By David Surratt; 'If you are interested in FRC, or even just in chess history - buy this book.' The next is on Jeremysilman.com (2004; 'Shall We Play Fisher Random Chess?'): Reviewed by John Donaldson; 'If you have any interest in random chess you will want to get Gligoric's book.' The most recent is a discussion on a Chess.com forum (2010): Interesting Chess960 FRC books; Milener surfaces again and presents his real opinion, 'I ask you honestly whether anything in Gligoric's Fischerandom book says anything at all about Fischerandom?', followed by a few concepts from his own book.
My favorite section of the book is a postscript to the eight games played between GMs Leko and Adams at Mainz 2001. There are comments on Fischer's version by Leko, Adams, Yusupov, Bronstein, Kasparov, and Kramnik. Here's Kramnik:
I tried many different starting positions and all these were somehow very unharmonious. And this is not surprising as in many of these positions there is immediate forced play: the pieces are placed so badly at the start that there is a need to improve their positions in one way only, which decreases the number of choices.
It's a good point and would provide an interesting kickoff for another post.
[In preparation for his 1992 match with Spassky], Bobby asked if I could play a training match with him. At first I didn’t want to, but I had to give in to his wishes. He was panicking about how theory had developed during his twenty-year absence from chess. That was why he came up with his own version of chess, where the starting position would be determined by the drawing of lots. And he began to torment me with persistent requests to write a book about it.
I told Bobby that I had very little information, but he wouldn’t let it go: "Write that book! You have to do it!" In the end I started to gather a few crumbs of material, and a few years ago a book on "Fischer Random Chess" was published in London.
There I wrote that "Fischer Random Chess" would never replace classical chess, but could exist in parallel with it. And I turned out to be right: there are now tournaments in Fischer Random Chess, and moreover great success has been achieved in it by the same players who play well in classical chess.
I don’t think that classical chess will ever die out. Capablanca feared the spectre of the "draw death" of chess, while Fischer feared the rampant expansion of theory. Perhaps a time will come when grandmasters can’t think up anything new in the opening, but then the struggle’s centre of gravity will shift to the middlegame, and the endgame. To a degree we can already observe a situation like that now.
Before seeing this, I hadn't known that Fischer had any connection with Gligoric's book. I should have guessed.
Another curious pattern is where the rightmost Rook starts on the e-file. There are 102 such positions, shown in the following table (the second column is the count of chess960 positions that share that pattern).
R**KR*** 18
*R*KR*** 18
**RKR*** 18
R*K*R*** 12
*RK*R*** 18
RK**R*** 18
These patterns are special because castling O-O displaces the Rook from the central e-file to the off-center f-file, at the risk of undeveloping it. From the f-file, it might have to be moved back to its start square by Rf1-e1 (or Rf8-e8). When this happens, castling O-O actually loses a tempo. In cases where the Rook is already performing an important duty, the move O-O might even be too dangerous to consider.
This quirk doesn't happen with castling O-O-O. When the Rook starts on the d-file, as in the following patterns, the O-O-O move leaves the Rook in place, where it is often already active.
***RKR** 18
***RK*R* 18
***RK**R 18
Considerations like these make the castling move so important to chess960. That's why I always consider the castling options when evaluating a new start position.
RKR***** 18
RK*R**** 18
RK**R*** 18
RK***R** 18
RK****R* 18
RK*****R 18
R*KR**** 18
R*K*R*** 12
R*K**R** 18
R*K***R* 12
[...]
***R**KR 18
****RKR* 18
****RK*R 18
****R*KR 18
*****RKR 18
The number in the second column is the count of different chess960 positions that share that unique castling pattern. For example, there are 18 positions that have the 'RKR*****' pattern and 12 that have 'R*K*R***'. In the previous post I worked out why some castling patterns encompass 18 positions (there are 48 such patterns) and others only 12 positions (8 patterns). It has to do with positions where the R, K, & R all start on squares of the same color.
The same type of visual table can be used to show the number of positions where castling is possible on the first move. There are 72 positions where castling O-O-O is immediately possible:-
**RKR*** 18
**RK*R** 18
**RK**R* 18
**RK***R 18
And there are 90 positions where O-O is immediately possible:-
R****KR* 18
*R***KR* 18
**R**KR* 18
***R*KR* 18
****RKR* 18
Some day it might be interesting to examine patterns from real games and determine how many times the players castled O-O-O vs. O-O. For now, though, there are too few recorded games to make this worthwhile.
The first batch of examples consisted of ten games played in CCM9 during the first round of the 8th FiNet Open. Because the event used the Swiss system for pairings, the highest rated players, all GMs, were paired against the top players from the bottom half of the rankings. This was similar to the situation I discussed in GMs vs. 2100-2200 (I) and GMs vs. 2100-2200 (II).
The second batch of games came from the eighth round of the same event, where the GMs played against each other. This reminded me of the post How Top Players Treat the Same Chess960 Position. The games played in the second batch used the start position shown in the following diagram. I featured one of these games in the post Grischuk - Mamedyarov, Mainz 2009.
SP535 RNBKQNRB
The initial moves show considerable variety, but are drawn from the most popular moves used in the traditional start position.
( 1.g3 g6 2.e4
( 2.c4 e5 3.Nc3 Ne6 4.d3 c6 5.Bh6 g5 {Grischuk - Mamedyarov} )
( 2.d3 e5 3.c4 Ne6 4.Nc3 c6 5.b3 Qe7 {Navara - Moiseenko} )
2...e5
( 2...d6 3.Ne3 Nc6 4.f4 Bd4 5.c3 Bb6 {Bologan - Buhmann} )
3.d3 d6 4.Nc3 Ne6 5.Bd2 Nd4 {Kamsky - Grigoriants} )
( 1.Nc3 g6
( 1...g5 2.g3 d6 3.b3 Nc6 4.Bb2 f5 {5.O-O-O Bd7; Azarov - Akopian} )
2.g4 e5 3.b3 Nc6 4.Bb2 d6 {5.O-O-O Be6; Movsesian - Sargissian} )
( 1.e4 g6 2.Ne3 b6 3.Nc3 Bb7 4.g3 Nc6 5.b3 e6 {Landa - Malakhov} )
( 1.f4 g6 2.g4 c5 3.Nc3 Nc6 4.d3 b6 5.Bd2 Bb7 {Naiditsch - Stevic} )
( 1.d4 g6 2.Be3 e5 3.dxe5 Qxe5 4.Nc3 Ne6 {5.O-O-O O-O; Nielsen - Zvjaginsev} )
( 1.c4 e5 2.g3 d6 3.d3 Nc6 4.Nc3 Nd7 5.Bg5+ f6 {Gashimov - Sebag} )
Other than releasing the Bishop on h1, I don't see any reason why 1.g3 should have been such an overwhelming favorite. It was chosen by four of the world's best players.
