jomega
Strategic Test Suite (STS): STS(v6.0) Recapturing.022
Which recapture? Also, an alternate best move is cooked.A continuation of the discussion started here:
jomega's Blog • Strategic Test Suite (STS): The EPD file's best and alternate best moves. • lichess.org
Another interesting position for which Stockfish 14 failed to find the best move in the 3 second (depth 26) test.
The Human Perspective
Recapturing with the Knight causes an immediate crises because of the threat of ...Rxb3. For reasons explained in the study, White is practically forced to take the Knight with his Bishop. The recapture with the c-pawn gives a position that greatly favors Black. White has a weak backward b-pawn, weak dark squares, the problem of the half-open h-file, and the protected passed d4-pawn to watch. Black can easily get his "bad" Bishop outside the pawn mass in the center. This choice of recapturing with the Knight also maintains tension in the position.
Stockfish's Perspective
Stockfish prefers recapturing with the c-pawn. Stockfish's search shows that for the cost of the Black a-pawn, Black gets an attack on both sides of the board. Stockfish's main variation also has the Bishops exchanging because of a tactical threat, hence that variation leaves Black with a powerful Knight.
Knight or Bishop Here; Which do you prefer?
Both variations win.
The Cooked Move 1...Ng5.
This alternate best move is a blunder that lets White win. It should be removed from the EPD file.
Links
- The Strategic Test Suite (STS) home page.
https://sites.google.com/site/strategictestsuite/
- The STS-rating code.
https://github.com/fsmosca/STS-Rating