Jerome Gambit: What's He Got?

If there is anything to the Jerome Gambit - and that can be seriously debated either way - then Black needs to quickly decide if he will a) return material that is "rightfully" White's to claim or b) hang on to his bounty and wait for White to "prove" the validity of his gambit. Of course, giving Black reason to debate to himself, "a) or b), a) or b), a) or b)?" complicates the defender's task, and sometimes even burden's his clock.

For example, in the following game, what is White up to with his Queen check at move 8?

What follows is quite a battle, and Black has his chances - as is always the case in the Jerome - but, in the end, White prevails. 

Wall, Bill - Guest3467690
PlayChess.com, 2017

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bxd4 7.Qxd4 d6 8.Qd5+

Here, Black has to decide, is his b-pawn part of the fair and logical compensation for White's sacrificed piece? If it is, then Black is going to have to let the pawn go. If it isn't, then Black has no reason to allow his opponent to grab it - he should either duck the 8...Be6 9.Qxb7 line, or realize that the pawn is poisoned and prepare a refutation.     

8...Ke8 

He ducks. Not every one of Bill's opponents has done so, although it is unclear how much time the decision cost them:

8...Be6 9.Qxb7 Nf6 10.Nc3 (10.Nd2 a5 11.f4 Nc4 12.Nf3 Re8 13.O-O Nb6 14.Bd2 Bc4 15.Be3 Rb8 16.Qa7 Bxf1 17.Rxf1 Kg8 18.e5 Nfd5 19.Bd4 Qc8 20.Qxa5 c5 21.Bf2 Nc4 22.Qe1 Nxf4 23.Be3 Nxe5 24.Nxe5 dxe5 25.Bxf4 exf4 26.Qc3 Qe6 White resigned, Wall,B - Guest774156, PlayChess.com, 2016; 10.f4 Ned7 11.Nc3 Rf8 12.O-O Kg8 13.b3 Nh5 14.Be3 Nc5 15.Bxc5 dxc5 16.Rad1 Qe7 17.Nd5 Bxd5 18.Qxd5+ Kh8 19.Qxh5 Qxe4 20.Qxc5 h6 21.Rde1 Qg6 22.Qxc7 Rac8 23.Qxa7 Rxc2 24.Rf2 Rcc8 25.g3 h5 26.Re7 Rg8 27.f5 Qg5 28.f6 Rc1+ 29.Kg2 Qd5+ 30.Kh3 Rc2 31.Rxg7 Qe6+ 32.Kh4 Qe4+ 33.Rf4 Rxh2+ 34.Kg5 Qe5+ 35.Kh6 Rxg7 36.Qxg7 checkmate, Wall,B - Javier, lichess.org, 2016) 10...Re8 11.O-O Kg8 12.b3 Bc8 13.Qxa8 Black resigned, Wall,B - Guest3335651, PlayChess.com, 2017. 

By the way, there are other ways to "duck" the return of a pawn,  about equal to the text move, and Bill has met a couple:

8...Ke7 9.Bg5+ Nf6 10.f4 Nc6 11.Nc3 Be6 12.Qd3 Re8 13.O-O Kf7 14.f5 Bd7 15.Nd5 Ne5 16.Qb3 Kf8 17.Rad1 Bc6 18.Nxf6 gxf6 19.Bh6+ Ke7 20.Qe6 checkmate, Wall,B - NN, lichess.org, 2016; and

8...Kf8 9.O-O Nf6 10.Qd4 Nc6 11.Qd3 Qe7 12.Nc3 h6 13.Bf4 g5 14.Be3 Kg7 15.f4 Ng4 16.Nd5 Qd8 17.Bd4+ Kh7 18.e5+ Kg8 19.Qg6+ Kf8 20.fxg5+ Black resigned, Wall,B - Guest344942, PlayChess.com, 2013 

9.Nc3 

Or 9.O-O Nf6 10.Qb3 Qd7 11.Nc3 Qe6 12.Qb5+ Ned7 13.Be3 a6 14.Qa4 Kf7 15.Rad1 Re8 16.Rfe1 Kg8 17.f4 b5 18.Nxb5 axb5 19.Qxa8 Qxe4 20.Qxe4 Rxe4 21.Rd4 Rxd4 22.Bxd4 Kf7 23.a4 bxa4 24.Ra1 Nd5 25.Rxa4 c5 26.Bf2 Ke7 27.Bh4+ Ke6 28.g4 g6 29.Kf2 Nb4 30.Ra8 Nb6 31.Rb8 N4d5 32.Bd8 Kd7 33.Bxb6 Nxf4 34.Kf3 Nd5 35.Ba5 Ne7 36.Rb3 Kc6 37.Bd8 Nd5 38.c4 Nb4 39.Ba5 Nc2 40.Kf4 Nd4 41.Rb8 Black resigned, Wall,B - Tankins, PlayChess.com, 2016. 

9...Nf6 10.Qb3

I am always amazed at how Bill's Queen wanders.

This is another occasion for Black to get lost in thought: Is White's placement good or bad? Can I take advantage of it? How?  

10...c6 11.f4 Nh5 

Black decides: it is time for action on the unprotected Kingside.

12.O-O

Bill decides to stay away from the wild line: 12.fxe5 Qh4+ 13.g3 Nxg3!? 14.Bg5!? Qxg5 15.hxg3  Qxg3+ 15.Kd2 Qf4+ 16.Kd3 Qxe5 when Black would have the better game (two extra pawns, safer King).

Can his pawns protect his King until the Queen returns?

12...Ng4 13.h3 Ngf6 14.e5 

Wow. Stockfish 8 is not impressed with Black's counter attack, recommending now 14...Qb6+, followed by 15.Rf2 Qxb3 16.axb3 Kf7 17.exf6 Nxf6 with an even game. The issue: Black's Knights are tripping over each other.

14...Nd7 15.Be3 d5 16.g4 

Logical and thematic. Stockfish 8 suggests, instead, either 16.Rad1 or 16.f5 and gives lines that devolve into even positions. Bill wants to push things a bit.

16...Ng3 17.Rf3 Ne4 18.Nxe4 dxe4 19.Rf2 Qh4 

20.Kh2 Nb6 

Although White has chased off from the Kingside Black's Knights, the danger there has not evaporated, as this move, which threatens ...Bxg4, shows. 

21.e6 Nd5 

Blocking White's protection of the pawn on e6, which in turn was impeding Black's Bishop. Probably better was the paradoxical withdrawal of the Queen with 21...Qf6, followed, after  22.f5 by 22...h5!? when the inclusion of the Rook in the attack on White's King would begin to look scary. 

22.f5 Nxe3 23.Qxe3 

23...Ke7 

Blockading the enemy pawn.

Black does not realize that all of White's "Jerome pawns" will come into play now. Stockfish 8 recommends play that gives drawing chances (it is surprising how often this happens): 23...Rf8 24.Rf4 h5 25.Rd1 hxg4 26.Rxg4 Qh5 27.Qd4 Bxe6 28.fxe6 Qd5 29.Rxe4 Qxd4 30.Rexd4 Ke7 31.Rd7+ Kxe6 32.R1d6+ Ke5 33.Rd2 b6 34.Rxg7 c5 35.Re7+ Kf6 36.Re3 Rf7 37.h4 Kg7 38.Rg2+ Kh6 39.Kh3.

24.g5 Rf8 25.Rg1 Bxe6 26.Rf4 Qh5 27.Qxe4 g6 

Black returns the extra piece in a most unfortunate way - by allowing checkmate.

28.Qxe6+ Kd8 29.Qd6+ Kc8 30.Qxf8+ Kc7 31.Qe7+ Kb6 32.Rb4+ Ka6 33.Qxb7+ Ka5 34.Ra4+ Kxa4 35.Qxc6+ Ka5 36.b4+ Kxb4 37.Rb1+ Ka3 38.Qa6 checkmate