Jerome Gambit: The Best "Explanation"

The previous post suggested that

Often the best way to learn an opening is to play over the games of an experienced practitioner 

True, that, but sometimes a game becomes very complicated, and the best "explanation" of what is happening is the series of moves that the winner plays. There is a way out of the maze, but sometimes it is not easy for the reader to discover it without help.

Wall, Bill - Guest423598
PlayChess.com, 2017

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Kf8 

Here we have another Sorensen variation where Black is satisfied with accepting one sacrificed piece. It remains an important defense - see "Critical Line: 5...Kf8 (1, 2 and 3)".

6.O-O Nxe5

This time Bill tempos with 6.0-0, and his opponent changes his mind and grabs the second piece.

Alternately Bill has faced:

6...Qf6 7.Nxc6 (White goes back to the main idea) Qxc6 (7...dxc6 8.Nc3 Bd6 9.d4 h6 10.e5 Bxe5 11.dxe5 Qxe5 12.Re1 Qg5 13.Bxg5 Black resigned, Wall,B - NN, lichess.org, 2016) 8.d4 Bb6 9.Nc3 d6 10.Bg5 Qe8 11.f4 Qg6 12.h4 Qe8 13.f5 Ba5 14.f6 gxf6 15.Qf3 Qf7 16.Nd5 h5 17.Bxf6 Nxf6 18.Nxf6 Be6 19.Qg3 Ke7 20.Nd5+ Bxd5 21.Rxf7+ Bxf7 22.Qg5+ Kd7 23.Qxa5 b6 24.Qb5+ c6 25.Qf5+ Be6 26.Qf6 Rh7 27.d5 cxd5 28.exd5 Bg4 29.Re1 Rg8 30.Re3 Rc8 31.a4 Rc7 32.a5 bxa5 33.Re6 Rc5 34.Rxd6+ Kc7 35.Rc6+ Rxc6 36.Qxc6+ Kd8 37.d6 a4 38.Qa8+ Bc8 39.c4 Rb7 40.c5 Rg7 41.Qf3 Rg6 42.Qf7 Re6 43.c6 Ba6 44.Qd7 checkmate, Wall,B - Computer-level 6, Chess.com, 2017 and

6...d6 7.Nxc6 bxc6 8.d4 (8.Nc3 Nf6 9.d4 Bb4 10.Qf3 Bg4 11.Qf4 Kg8 12.e5 Bxc3 13.exf6 Qd7 14.bxc3 Bf5 15.Qg3 Bxc2 16.Bh6 g6 17.Rfe1 Qf5 18.Re7 Qxf6 19.Rae1 Bf5 20.Rxc7 Rb8 21.h3 Rc8 22.Qe3 Rf8 23.Qe7 Qf7 24.Qxf7+ Rxf7 25.Re8+ Rf8 26.Rxf8 checkmate, Wall,B - Anonymous, lichess.org, 2016) 8...Bb6 9.Nc3 Ba6 10.Re1 Qf6 11.e5 Qh4 12.Re4 Qe7 13.Qf3+ Qf7 14.Rf4 Qxf4 15.Bxf4 d5 16.Bh6+ Ke7 17.Bxg7 Black resigned, Wall,B - Guest399227, PlayChess.com, 2016. 

7.d4 Bb6 

It is sometimes useful to search for understanding in a line by looking at and comparing transpositions.

For example, suppose instead of playing 5...Kf8, Guest423598 had tried 5...Nxe5 and after 6.d4 had played 6...Bb6, with White following up with 7.O-O as in the current game - well, there are actually 3 games by jfhumphrey (he has 278 games in The Database) with that line, and it is significant that two continue with 7...Ng6 and one continues with 7...Nc6; in none of the cases did Black feel the need to play ...Kf8, which would transpose to the current game.

Does that leave Black in our current game a tempo behind the jfhumphrey games, or is his King safer on f8 versus f7?

Of course, experience and analysis suggest that the more critical misstep for Black was withdrawing the Bishop, rather than giving it up in exchange for White's d-pawn, i.e. 7...Bxd4 8.Qxd4 Qf6 9. Qe3 Ne7 10. Nc3 d6 11. f4 N5c6 12. Nb5 Ng6 13. Nxc7 Rb8 14. Nb5 a6 15. e5 Qe6 16. f5 Qxe5 17. fxg6+ Kg8 18. Nxd6 hxg6 19.Qxe5 Nxe5 20.Bf4 Rh5 21.Rae1 Black resigned, Wall,B - Guest1442, chesstempo.com, 2017.

Black would also have done better giving up the Knight, e.g. 7...Bd6 8.dxe5 Bxe5 9.f4 Bd4+ 10.Qxd4 Qf6 11.e5 Qb6 12.Qxb6 axb6 13.Nc3 Ne7 14.Nb5 c6 15.Nd6 g6 16.f5 gxf5 17.Bh6+ Kg8 18.Nxf5 Nxf5 19.Rxf5 d5 20.Rf8 checkmate, billwall - DeDrijver, Chess.com, 2012. 

8.dxe5 Qe8 9.Qf3+ Qf7 10.Qa3+ Ne7 11.Nc3 c6 

Black's Bishop plans to retreat and protect the pinned Knight.

12.Bg5 

Applying pressure. Oddly, Stockfish 8 suggests 12.Be3 Bc7 13.f4 Qc4 14.Rad1 b5 15.Rd4 Qf7 16.Rd2 Qc4 17.Rd4 etc. with a draw by repetition. I can't see either human player being satisfied with that.

12...Bd8 13.f4 h6 14.Bh4 Ke8  

Defending in Steinitz-like fashion, Black now anticipates trouble along the f-file, and moves his King off of it. Stockfish 8 suggests that the King belongs at h7, instead, in a rather turgid, if balanced, position.

Jerome Gambit players should decide: how should White continue?

15.f5 g5 

Not fearing 16.fxg6 ep Qxg6 with an open line against the White King, although the attack would develop slowly.

16.Bg3 b5  

Black wants to work around the central "Jerome pawns" by advancing on the wings. It is an interesting idea, but also a dangerous one, as his King is stuck in the center and vulnerable to a pawn break through.

I have to say that Black's psychology would have me raving with impatience with the White pieces - but Bill Wall is a cool character, and he decides to occupy a "hole" in his opponent's position.

17.Qd6 Bb7 

And, just like that, Black's position blows up.

Upon reflection, 16...b5 was a mistake. Should he have gone all in with 16...h5, and pushed the Kingside attack?

Should he have avoided the g-pawn push on move 15 and noodled around with something like 15...Bc7, instead? 

Was 14...Kg8, headed toward h7, the way to go after all?

The best that Stockfish 8 can come up for him now is 17...Qf8 18.e6 Nxf5 19.exd7+ Bxd7 20.Qg6+ Qf7 21.exf5 Qxg6 22.fxg6  with a very exposed King. 

18.e6 dxe6 19.fxe6 Black resigned

Black will have to give up his Queen to avoid checkmate.