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 Comment	Long Comment	Eval
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.