Jerome Gambit: The Future Is Here

Last month I received an email from Mitchell Jansen, who noted

I recently discovered your blog about the Jerome Gambit and I was surprised by the amount of research you have put into it. I was hoping that I could help add to that by submitting a game played by two of the top chess engines in circulation today. Hopefully, through careful analysis of this game, we will be able to understand better the intricacies of the Jerome Gambit in the Giuoco Piano.

The two chess engines in the game were Stockfish and Leela Chess Zero. I was not familar with the latter, so I sought an explanation from Wikipedia

 Leela Chess Zero (abbreviated as LCZero, lc0) is a free, open-source, and neural network-based chess engine and distributed computing project. Development has been spearheaded by programmer Gary Linscott, who is also a developer for the Stockfish chess engine. Leela Chess Zero was adapted from the Leela Zero Go engine, which in turn was based on Google's AlphaGo Zero project, also to verify the methods in the AlphaZero paper as applied to the game of chess. 

Like Leela Zero and AlphaGo Zero, Leela Chess Zero starts with no intrinsic chess-specific knowledge other than the basic rules of the game. Leela Chess Zero then learns how to play chess by reinforcement learning from repeated self-play, using a distributed computing network coordinated at the Leela Chess Zero website. 

As of 2020, Leela Chess Zero had played over 300 million games against itself, and is capable of play at a level that is comparable with Stockfish, the leading conventional chess program.

Interesting! Lc0 was listed as having an Elo rating of 3616, while Stockfish 11 was rated at 3604 - indeed, the highest rated Jerome Gambit game that I had ever heard of. I invited a third computer chess program, Komodo 10 (rated in the mere 3300s), along, and decided to take a look.

Lc0 - Stockfish 11
45 15 computer chess, 2020

Stockfish 11 was running on an Intel Core i7-8750H CPU at 2.20GHz with 16 GB of RAM while lc0 was running on an NVIDIA GeForce GTX 1070 GPU. 

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6

7.Qf5+ Kd6 8.f4 Kc6 

Defenders, take note.

9.Qxe5 Nf6 10.d4 

This is a typically aggressive Jerome Gambit move, that, superficially, blocks Black's dark-square Bishop, which is essential for White to castle. However, Komodo 10 was suspicious, preferring 10.d3, realizing that castling will not be possible, and resisting what danger might come down the e-file.

The Database has only 3 previous games with 10.d4, all wins by Black. This may be a result of 8...Kc6, which also only appears in those games.

10... d6 11.Qg5 

This is a new move, and, again, Komodo 10 disagrees - it is rated 300 points lower, of course it would disagree. It prefers 11.d5+ Kb6 12.Qc3 and a pursuit of the enemy King on the Queenside.

11...Bxd4 12.Qa5 Bc5 13.b4 Nxe4 

Stockfish willingly returns a piece, as White's Queen switch to the other side of the board leaves White' King at great risk.

14.bxc5 Qh4+ 15.g3 Nxg3 16.Be3 Nxh1+ 17.Kd2 Qxh2+ 18.Kc1 Ng3 

19.Nc3 Ne2+ 20.Kb2 Nxc3 21.Qxc3 d5 22.Rd1

White plays on, down a Rook. It no longer matters that Komodo 10 suggested 22.Rg1, instead.

22...Qe2 23.Qd4 Qc4 24.Qxg7 Qb4+ 25.Ka1 Re8 26.Qf6+ Re6

27.Qd8 Rxe3 28.Qxd5+ Kb5 29.Rb1 Re1 30.a4+ Ka6 31.Rxe1 Qxe1+ 32.Kb2 Qb4+ 33.Ka2 Qxa4+ 34.Kb2 Qb4+ 35.Ka1 Qxf4 36.Qd3+ 

If this were a human vs human game, I suppose this would be referred to as a "spite check".

36...Ka5 37.c4 Qc1+ 38.Ka2 Be6 39.c6 Bxc4+ 40.Qxc4 Qxc4+ 41.Kb2 Rd8 42.Ka3 Qc2 43.cxb7 Rd3 checkmate.

To quote Sean Connery's character in the movie "Zardoz", "I have seen the future, and it doesn't work."