Stockfish On The Classics: Fischer's Bishop Sac

Chess engines have forced us to reevaluate many facets of the game. As each generation of engines grows stronger it's worth looking at some of the great moments in chess history to see which brilliancies hold up and which ones don't quite withstand the modern microscope.

We will start our series with one of the most famous moments in the history of the game, the start of the dramatic "Match Of The Century" between GM Bobby Fischer and GM Boris Spassky. It all starts in this quiet position below. What would you play for Black? I suspect it wasn't Fischer's insane-looking 29...Bxh2??!!

Why was Fischer's move so odd? Spassky immediately advanced his g-pawn to trap the bishop and quickly won the game. 

Fischer's crazy bishop sacrifice (or was it a blunder?) soon became a controversial moment in chess history. Did Fischer's nerves get to him and cause him to blunder a piece at the start of his first world championship match? Did he correctly evaluate the sacrifice and make a mistake later on? Fischer never wrote about the game, but analysts have been debating these questions for generations. 

Stockfish is the strongest chess engine, boasting an estimated rating of over 3500. It can help us resolve which authors best captured the critical moments of this amazing endgame.

What Does Stockfish Think?

The first big moment of debate comes in this position where White must decide between Spassky's 36.a4 and 36.Kg4, recommended by GM Garry Kasparov, Jan Timman, and others.

The engine isn't impressed with these great players and finds a path for Black to draw against Kg4. White just doesn't have quite enough pawns to win the game.

It turns out that Fischer was holding the draw for several moves after the sacrifice. His critical mistake wasn't until move 39....f5?? cost him the game. 39...e5! would have seen him survive. In the main line, Black captures all of White's pawns except for one and builds an impenetrable fortress.

You can check out full analysis of the endgame below. After Fischer advanced the wrong pawn on move 39, Spassky confidently converted his extra material to victory. After this disaster, Fischer no-showed the second game and forfeited, but still came back and won the match 12.5-8.5!

Are there any classic games that you would like to see analyzed? Let us know in the comments.