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Explaining Chess in Natural Language
tl;dr: We compare two moves, then explain in natural language why the stronger move is better.
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Vladimir Fedoseev vs Magnus Carlsen · June 19, 2014
Magnus played Nf8, but Stockfish prefers Qxa3.
22. Bxc3
Load PGN or FEN
Why Qxa3 beats Nf8
Qxa3leads to:
Present afterQxa3
White has permanent weak squares on g3 and b4 that its pawns can no longer challenge.
Absent afterNf8
Present afterQxa3
All of Black's major and minor pieces are secure: knights on b6 and d7, rooks on d8 and e8, and queen on d6. None is undefended under attack or attacked by a cheaper White piece, and White has no safe one-move attack with a cheaper piece against any of them. The development requirement is met by Black's knight on b6 and queen on d6.
Absent afterNf8
Present afterQxa3
White's king on b1 is less sheltered: White's king has pawn cover on b3, while Black's king has pawn cover on c6, a7, b7 around the king on b8.
Absent afterNf8
Nf8leads to:
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