27 August 2022


In a perfect world, this post would be a followup to the previous post 2022 FWFRCC Kickoff (August 2022; 'FIDE World Fischer Random Chess Championship'). That event will undoubtedly dominate the blog for the next few months, but first I have to tackle an outstanding topic before it becomes old news.

This post is more of a followup to last month's TCEC C960 FRC5 (July 2022), because it's also about the TCEC. It's in reference to a post on my main blog, Stockfish Wins TCEC DFRC1, Leads CCC18 Rapid Final (August 2022). As a summary of DFRC1, I wrote,

In DFRC1 ('Double Fischer Random Chess: (960*960) possible starting positions'), Stockfish and LCZero finished tied for 1st/2nd places with 16.0/22, 1.5 points ahead of KomodoDragon, which was 2.0 points ahead of Stoofvlees. In the 50 game final match, Stockfish beat LCZero 29.5-20.5 (+18-9=23). For more discussion of the event, see the next post on my chess960 blog.

I know, this isn't the 'next post' on this blog; it's the 'next+1 post'. The unexpected news about the FWFRCC took priority. To understand what the TCEC accomplished -- and it's without question a noteworthy accomplishment -- let's quote some TCEC !definitions [Warning! : Serious chess engine jargon ahead...]:-

!dfrc • Double Fischer Random Chess: The same as Fischer Random Chess [FRC; C960], except the White and Black starting positions do not necessarily mirror each other. Double FRC has 921,600 (960*960) possible starting positions. [Also has links to files for DFRC 'Openings' and 'Evals'.]

!dfrctest • Initial test of !DFRC at TCEC. To check a) engines handling of DFRC - see !bugs, b) some DFRC start positions, c) cutechess handling of DFRC, d) GUI handling of DFRC. Time control: 7 minutes + 1 second/move. Duration 1 week

!dfrc1 • 1.SF (on SB 196) 2.Lc0 (SB 192.5) 3. KD. 26 participants (FRC5 + Bagatur), Swiss format, games from starting positions, 11 rounds, and 30min+3s TC. Estimated duration: 12 days.

!bookdfrc • Selected 1600 opening positions for the DFRC event, and for the DFRC testing. These are the positions for which KD, Eth, Berserk and SF (the latter through dbcn) agree that white has about a 50% chance for a win. The selection was then further pruned using careful SF analysis.

!unbust • Took positions where starting position abs(eval) >= 2.00, 17739 DFRC positions. Played Stockfish 202206020749 200k vs Stockfish 100k and 8071 were still 'busted'. Played those 1M vs 100k and 1172 were left 'busted'. Played those 10M vs 100k and 83 were left 'busted'. Finally, those 100M vs 100k and 10 are still 'busted'. These will be used in Bagatur vs Stockfish bonus.

!chess324 • A subset of DFRC where the Kings and the Rooks are at the usual starting position. Since castling is standard, this allows all engines to play.

For more about that last definition, see Chess324 (talkchess.com; lkaufman, aka Larry Kaufman of Komodo++ fame). The dean of chess engines explained, 'The Kings and Rooks are placed on their normal positions. All the other pieces for White and Black are placed randomly, with no symmetry requirement, the only restriction being that for each side the Bishops must be on opposite colored squares.'

Chessbase weighed in on a related topic with Double Shuffle Chess: a fun variant against Fritz Online (chessbase.com; Albert Silver). In this variant the Kings aren't required to be between the Rooks and there is no castling. No thanks, I'll pass. Maybe the TCEC or the CCC will give it a try.

After that little detour, let's get back to the TCEC. For archive info (crosstables, PGN, etc.) about the DFRC1 events, see:-

Since I'm already following the TCEC, I'll keep an eye on their DFRC events. My first impression is that it's more for chess engine enthusiasts than for chess960 enthusiasts, but I was no fan of chess960 when it first appeared on my radar either.

1 comment:

Mark Weeks said...

Reply to nicbentulan comments in the Twitter anchor for this post (Twitter doesn't like long comments)


Re having to move one Rook in order to castle with the other, it's an interesting class of related start positions (SPs). I've played several games with those positions and enjoyed playing them. I remember a Nakamura game where he lifted the obstructing Rook to his second rank. It was a creative solution. Castling gave him doubled Rooks.

I'm always against eliminating positions because they create special difficulties not found in SP518. Some people want to eliminate Bishops starting in the corner; some want to eliminate Queens or Knights in the corner. Why eliminate a legitimate, although difficult, position? A player who can't improvise in unfamiliar situations with a creative strategy should stick to SP518. I call it the sandbox position.

There's another class of SPs which requires undeveloping a Rook, e.g. ***KR*** castles K-side to *****RK*. Would you eliminate those as well?

Re chess324, yes, that's right. See the Kaufman thread that I linked in the post. Three squares for one Bishop, times two squares for the other Bishop, times three squares for the Queen makes a total of 18 positions. Some people have proposed similar for chess960. Call it chess018? You might also allow the King to start on the d-file, but that prevents non-chess960 engines from playing.