25 February 2023

Chess.com Reviews a Chess960 Opening

In last week's post, Chess.com Pinpoints a Tactical Error (February 2023; see the post for a copy of the game's PGN), I used 'Chess.com's Game Review Tools' to find out where I had made the first mistake in losing a chess960 game. This week I'll use the same tools to extract comments on the opening moves.

The following diagram shows the start of the same game featured in the 'Tactical Error' post. There's more I can say about the look and feel of the 'Analysis' tool itself, but I'll save that for a series I'm doing on my main blog. The most recent post in that series was Chess.com's Game Review Tools PGN (February 2023).

Shown on the left is the start position for the game, 'SP350 NRKQRBBN'. On the right is a summary of the overall quality of the players' moves ('Brilliant', 'Great Move', ..., 'Blunder'). For example, the tool considers that both players made one 'Great Move'.

AV vs. bemweeks | Analysis (chess.com)

The following table shows the tool's comments on the first 12 moves of the game (24 ply deep). I stopped the analysis when I reached the move where I committed the 'Tactical Error'.

Move Short
1.e4 is excellent This prepares the bishop for development. This threatens to reveal an attack on a pawn. +0.13
1...e5 is good This prepares your bishop for development. +0.30
2.f4 is excellent This exposes an attack, threatening a pawn. +0.27
2...Nb6 is excellent Your piece jumps in to protect a pawn! +0.41
3.fxe5 is best Right on target. +0.41
3...f6 is an inaccuracy You are threatening to attack a trapped rook. +1.09
4.Nb3 is a mistake This loses a pawn. +0.05
4...fxe5 is best That wins a free pawn! +0.05
5.Ng3 is excellent One of the best moves. -0.02
5...Qf6 is best You activate your queen by moving it off of its starting square. -0.02
6.Be3 is good This moves the bishop to a better location, allowing it to control more squares. -0.30
6...O-O-O is good Your rooks can see each other now, allowing them to provide mutual defense. +0.02
7.d3 is best That's what I would have recommended. +0.02
7...d5 is best You are threatening to kick a bishop. +0.02
8.Qd2 is an inaccuracy This ignores a better way to develop a queen off its starting square. -0.47
8...Qc6 is good You are threatening to kick a bishop. -0.10
9.Bg5 is good This wins a tempo by threatening a rook and forcing it to move away. -0.38
9...Be7 is a mistake You are threatening to win material. +0.56
10.Bxe7 is best After all captures, this is an equal trade. +0.56
10...Rxe7 is best You trade off equal material. +0.56
11.Nf5 is good This attacks a rook, winning a tempo when it moves away. This threatens to fork pieces. +0.27
11...Red7 is good You have now doubled your rooks, allowing them to team up to create threats. +0.62
12.exd5 is best This exposes an attack, threatening a pawn. +0.62
12...Qxd5 is a mistake You overlooked a better way to recapture a piece. +1.63

There's much more I could say about the comments, but it would not be useful at this point. Here are a few comments that jumped off the screen at me.

  • 8...Qc6; 'You are threatening to kick a Bishop.' • The move defends against a nasty x-ray threat.

  • 9.Bg5; 'This wins a tempo by threatening a Rook and forcing it to move away.' • The move doesn't win a tempo, but it might lose a tempo by forcing the Rook to a better square.

  • 9...Be7; 'Is a mistake. You are threatening to win material.' • It's a mistake to win material? Something does not compute here.

And so on. The long comments are generally lame and show little understanding of chess960 opening objectives. What happened in the fight for the center?

The most valuable part of the exercise is to see the change in evaluation from one move to the next. It reaffirms the severity of my mistake on the 12th move.

18 February 2023

Chess.com Pinpoints a Tactical Error

In last month's post, The Fascinating World of Chess960 (January 2023), I discussed a shift in focus for my own chess960 games. In a nutshell, to play chess960 I switched from a site allowing engines to a site forbidding them. I finished the post saying,
That's the background for a series of posts that I plan to write for my games on Chess.com. There are several aspects to be covered, e.g. Game review tools

I introduced those tools on my main blog in Chess.com's Game Review Tools (February 2023), using an example chess960 game. I'll use the same game in this current post. After four wins, it was the first game I lost on Chess.com starting June 2022, when I adopted the no-engine approach.

The 'Game Review Tools' post used numbers to identify the different screen shots and I'll follow the same numbering scheme in this current post. There are three different review tools that I numbered '02', '03a', and '05a'. The '02' tool shows the moves of the game and the times used for each move. It also provides (1) an entry into the '03a' and '03b' tools, and (2) a PGN download of the moves of the game, without variations or comments.

At this point, I don't see much difference between the '03a' and '05a' tools. The differences seem mainly cosmetic, so I'll continue with the '05a' tool. It's accessed via a feature called 'Saved Analysis'. In the game I was outplayed tactically and didn't know where I had gone wrong.

I had Black in a game starting 'SP350 NRKQRBBN'. I was pleased with my position after the first few moves and thought that I had equalized, maybe even gained a slight advantage. Then suddenly I had an inferior game. Why?

The '03a' and '05a' tools offer commentary on each move played in the game. I won't discuss the early comments in this post, because I'm not yet convinced they are helpful. The critical position is shown in the following screenshot, Black to move.

AV vs. bemweeks | Analysis - Chess.com • After 12.e4-d5(xP)

White has just captured a Pawn on d5 with 12.exd5, and Black has four possible recaptures. The move 12...Rxd5 is a '??' blunder, allowing the family fork 13.Ne7+. That leaves three other moves. Since White's last move also discovered an attack on the e5-Pawn, I played 12...Qxd5, protecting that Pawn. That was a mistake, which the tool flags with the remark '(?) Qxd5 is a mistake'.

What's better? The tool suggests 12...Nxd5. Now if 13.Rxe5, Black has 13...Qf6, when White is in trouble. I didn't see that possibility during the game and never recovered. Following is the PGN as provided by the '02' tool.

[Event "Let\\'s Play! - Chess960"]
[Site "Chess.com"]
[Date "2022.07.05"]
[Round "?"]
[White "Andreasvinckier"]
[Black "bemweeks"]
[Result "1-0"]
[Variant "Chess960"]
[SetUp "1"]
[FEN "nrkqrbbn/pppppppp/8/8/8/8/PPPPPPPP/NRKQRBBN w EBeb - 0 1"]
[WhiteElo "1977"]
[BlackElo "1907"]
[TimeControl "1/86400"]
[EndDate "2022.07.23"]
[Termination "Andreasvinckier won by resignation"]
[initialSetup "nrkqrbbn/pppppppp/8/8/8/8/PPPPPPPP/NRKQRBBN w EBeb - 0 1"]

1. e4 e5 2. f4 Nb6 3. fxe5 f6 4. Nb3 fxe5 5. Ng3 Qf6 6. Be3 O-O-O 7. d3 d5 8. Qd2 Qc6 9. Bg5 Be7 10. Bxe7 Rxe7 11. Nf5 Red7 12. exd5 Qxd5 13. Ne3 Qc6 14. g3 Be6 15. Qa5 Bxb3 16. axb3 e4 17. Bh3 exd3 18. O-O-O dxc2 19. Bxd7+ Rxd7 20. Rxd7 Qxd7 21. Qxa7 Nf7 22. Qa5 Nd6 23. Nd5 1-0

The Chess.com tools offer several different PGN downloads. I'll discuss those in another post on my main blog.