In 1961, Bobby Fischer became upset at a loss against the King’s Gambit and he analyzed the opening. He subsequently published an article titled “A Bust to the King’s Gambit”. In that article, Bobby explained the moves that, he believed, would make the King’s Gambit refuted.
I have been seeing a fair number of King’s Gambit openings when I play as black. I needed a reliable defense against this opening. This lead me to look at Bobby Fischer’s refutation of the King’s Gambit.
Bobby published a remarkable series of moves, especially considering that he did this without access to our modern computers. I put the moves into a database and allowed Houdini to review his findings. Everything looked great until move #11, where Houdini disagreed with 11...Nxe4, finding that this move gave back Black’s gains and equalized the game. Houdini preferred 11...Nxd4 12.cxd4 and only then 12...Nxe4. Here is Bobby’s refutation:
In case anyone wants to verify this with their own chess engine, the position after 11.Nxg5 is the FEN:
r1b1k2r/ppp1qpb1/2np1n2/6N1/2BPPp2/1QP5/PP4P1/RNB2RK1 b kq - 0 11