The following game shows White grabbing the initiative and pressing for advantage. This forces Black's pieces back, and then the defender is unable to deal with what follows.
Wall, Bill - anonymous
lichess.org, 2020
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb6
A reasonable response.
7.dxe5 Qh4
This might look surprising, but Bill was 7-0 against it before this game.
8.Qf3+ Ke8 9.Nc3 c6
Bill has also seen
9...Ne7 10.O-O (10.g3 Qh3 11.Be3 d6 12.Bxb6 cxb6 13.exd6 Ng6 14.Nd5 Qd7 15.Nc7+ Kd8 16.Nxa8 Qxd6 17.Rd1 Ne5 18.Rxd6+ Ke7 19.Qc3 Kxd6 20.Qd4+ Ke6 21.Nc7+ Kf7 22.Qxe5 Rd8 23.Nb5 Bg4 24.Qf4+ Kg8 25.Qxg4 a6 26.Qe6+ Kh8 27.Nd6 Rb8 28.Nf7+ Kg8 29.Nh6+ Kh8 30.Qg8+ Rxg8 31.Nf7 checkmate, Wall,B - Itboss, lichess.org, 2016) 10...Rf8 11.Qe2 Ng6 12.Be3 Nf4 13.Qd1 Qg5 14.g3 Nh3+ 15.Kg2 Nf4+ 16.Bxf4 Rxf4 17.Qd2 Rg4 18.Qd5 c6 19.Qg8+ Ke7 20.f4 Qh6 21.f5 Qd2+ 22.Kh1 Qxc2 23.Rad1 Rxe4 24.f6+ gxf6 25.exf6 checkmate, Wall,B - Guest5595814, PlayChess.com, 2018; and
9...Bxf2+ 10.Qxf2 Qxf2+ 11.Kxf2 Nh6 12.Nd5 Ng4+ 13.Kg3 Kd8 14.Bg5+ Nf6 15.exf6 h6 16.fxg7+ Ke8 17.gxh8=Q+ Kf7 18.Rhf1+ Kg6 19.Qxh6 checkmate, Wall,B - Shillam, lichess.org 2016
10.Bf4 Ne7 11.Bg3 Qh6 12.O-O Rf8 13.Qd3 Ng6
14.Rad1 Nf4 15.Qd2 Ne6 16.Qd3 Qg6 17.b4 Kf7 18.Na4 Kg8 19.Nxb6 axb6
Black has castled-by-hand.
White starts his pawns forward to grab the initiative.
20.f4 Nc7 21.f5 Qf7
The Queen would be safer at h5.
22.e6 dxe6 23.fxe6 Qxf1+
A tactical oversight.
24.Rxf1 Rxf1+ 25.Kxf1 Bxe6
After 25...Nxe6, Black would have a Rook and a Knight for a Queen and a pawn.
26.Bxc7 Black resigned
The difference between a very strong counter in the Jerome Gambit at move 6 and an ineffective defensive line (the same move one tempo later) shows the problem with delaying an active riposte.
Wall, Bill - Guest6766281
PlayChess.com, 2017
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb6
Black can decide which piece to save, the Bishop or the Knight. The text is a reasonable line.
Of course, Black's strongest response is to ignore both of the pieces and play 6...Qh4!?, what I have referred to as a pie-in-the-face variation.
7.dxe5 Qh4
A delayed pie-in-the-face? Tossing pies is very much a part of slapstick humor - and timing is always critical in comedy.
This line has been faced by Jerome Gambiteers chessmanjeff, frizerkaHR, GOH, HauntedKnight, jfhumphrey, ndrwgn, stretto, Wall and yorgos. As a group, they have not been impressed.
8.Qf3+ Ke7
A slightly better retreat is 8...Ke8, e.g. 9.Nc3 (9.O-O Ne7 10.Nc3 Rf8 11.Qe2 g5 12.Be3 Ng6 13.Nd5 Kd8 14.Qd2 h6 15.Bxb6 axb6 16.Nxc7 Kxc7 17.Qd6+ Kd8 18.Qxg6 Re8 19.Qxb6+ Ke7 20.Qf6 checkmate, Wall,B - Guest2616286, PlayChess.com, 2017) 9...Ne7 (9...Bxf2+ 10.Qxf2 Qxf2+ 11.Kxf2 Nh6 12.Nd5 Ng4+ 13.Kg3 Kd8 14.Bg5+ Nf6 15.exf6 h6 16.fxg7+ Ke8 17.gxh8=Q+ Kf7 18.Rhf1+ Kg6 19.Qxh6 checkmate, Wall,B - Shillam, lichess.org, 2016) 10.g3 Qh3 11.Be3 d6 12.Bxb6 cxb6 13.exd6 Ng6 14.Nd5 Qd7 15.Nc7+ Kd8 16.Nxa8 Qxd6 17.Rd1 Ne5 18.Rxd6+ Ke7 19.Qc3 Kxd6 20.Qd4+ Ke6 21.Nc7+ Kf7 22.Qxe5 Rd8 23.Nb5 Bg4 24.Qf4+ Kg8 25.Qxg4 a6 26.Qe6+ Kh8 27.Nd6 Rb8 28.Nf7+ Kg8 29.Nh6+ Kh8 30.Qg8+ Rxg8 31.Nf7 checkmate, Wall,B - Itboss, lichess.org, 2016.
9.Nc3
Or 9.O-O Nh6 10.Nc3 Rf8 11.Nd5+ Kd8 12.Qxf8 checkmate, Wall,B - Guest2293428, PlayChess.com, 2017.
9...Nh6 10.Nd5+ Kd8
Once again, e8 is the better square for the King.
11.O-O
White also has the sneaky 11.h3!? threatening g2-g3, winning the Queen. Black could escape by returning a piece for two pawns, i.e. 11...Bxf2+ 12. Qxf2 Qxe4+ but White would be better.
For the record, 11.g3?! directly could be answered by 11...Qg4 and White does not gain much by exchanging Queens, while he would lose time if he movee his Queen to avoid the swap.
11...Bd4
Looking to grab the pawn at e5, but he is overlooking a few things. He could have maintained an even game with 11...c6 12.Nxb6 axb6.
12.g3 Qh3
Why was e8 the better square for Black's King to retreat to (as suggested in the note to move 10)?
Why was the Black Bishop's trip to d4 problematic (as mentioned in the note to move 11)?
Why couldn't Black retreat his Queen to g4 (as in the note to move 11), instead of h3?
13.Bg5+ Ke8 14.Nxc7 checkmate
Gambits are all about development and attack. Failing to defend against gambits is often about lack of development, and its consequences. Witness the following game.
Wall, Bill - WGMS
FICS, 2017
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb6
Again, a reasonable line. See "A Reasonable Line".
7.dxe5 Ne7
Not the only line Bill has faced, to wit -
7...Qh4 8.Qf3+ Ke7 (8...Ke8 9.Nc3 Ne7 (9...Bxf2+ 10.Qxf2 Qxf2+ 11.Kxf2 Nh6 12.Nd5 Ng4+ 13.Kg3 Kd8 14.Bg5+ Nf6 15.exf6 h6 16.fxg7+ Ke8 17.gxh8=Q+ Kf7 18.Rhf1+ Kg6 19.Qxh6 checkmate, Wall,B - Shillam, lichess.org, 2016) 10.g3 Qh3 11.Be3 d6 12.Bxb6 cxb6 13.exd6 Ng6 14.Nd5 Qd7 15.Nc7+ Kd8 16.Nxa8 Qxd6 17.Rd1 Ne5 18.Rxd6+ Ke7 19.Qc3 Kxd6 20.Qd4+ Ke6 21.Nc7+ Kf7 22.Qxe5 Rd8 23.Nb5 Bg4 24.Qf4+ Kg8 25.Qxg4 a6 26.Qe6+ Kh8 27.Nd6 Rb8 28.Nf7+ Kg8 29.Nh6+ Kh8 30.Qg8+ Rxg8 31.Nf7 checkmate, Wall,B - Itboss, lichess.org, 2016) 9.Nc3 Nh6 10.Nd5+ Kd8 11.O-O Bd4 12.g3 Qh3 13.Bg5+ Ke8 14.Nxc7 checkmate, Wall,B-Guest6766281, PlayChess.com, 2017;
7...d6 8.O-O Be6 9.Qf3+ Ke8 10.Nc3 a6 11.Be3 dxe5 12.Qh5+ Bf7 13.Qxe5+ Qe7 14.Qxg7 Qf6 15.Bh6 Bd4 16.e5 Qg6 17.Qf8+ Kd7 18.Qxa8 Qxh6 19.Rfd1 c5 20.Qxb7+ Ke8 21.Qb8+ Ke7 22.Ne2 Bh5 23.Nxd4 Bxd1 24.Nf5+ Black resigned, Wall,B - TenAndOnly10, lichess.org, 2016; and
7...Qe7 8.Qf3+ Ke8 9.Nc3 Qxe5 10.O-O Nf6 11.Bf4 Qh5 12.Qg3 d6 13.Qxg7 Rf8 14.Nd5 Qf7 15.Bh6 Nxd5 16.Qxf8+ Qxf8 17.Bxf8 Kxf8 18.exd5 Bf5 19.c3 Re8 20.Rfe1 Be4 21.Rad1 Kf7 22.Kf1 Re5 23.f3 Bg6 24.Rxe5 dxe5 25.Ke2 e4 26.b4 exf3+ 27.Kxf3 Bh5+ 28.g4 Bg6 29.c4 a6 30.d6 cxd6 31.Rxd6 Bb1 32.Rxb6 Bxa2 33.Rxb7+ Ke6 34.Rb6+ Kd7 35.c5 Black resigned, Wall,B - NN, lichess.org, 2016.
8.Qf3+ Ke8 9.O-O Rf8 10.Qh5+ g6 11.Qxh7 g5 12.Qh5+ Rf7 13.Bxg5
Despite Black's dogged Kingside defense, it is likely that White's four pawns are worth more than Black's extra piece.
13...c6 14.Nd2 Qc7
Getting out of the pin on the Knight, but Black needed the freedom that would come with 14...d5.
15.Nc4
Targeting the d6 square, which Black overlooks.
15...a5 16.Nd6+ Black resigned
Black can avoid mate only by giving up his Queen.
The Jerome Gambit is full of "reasonable" lines of play for Black, and the defender has to be aware - is it a playable reasonable line, or an unplayable reasonable line; and then, more importantly, what comes next?
Wall, Bill - TenAndOnly10
lichess.org, 2016
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb6
This seems like a reasonable move, although not frequently played in comparison with other lines. It shows up in 111 games in The Database, where Black scores 50%. (Compare that to the 1,528 games with the same moves up until 6.d4, where Black scores 48%.)
Of course, any chance of catching Bill by suprise is likely to be small.
7.dxe5 d6
Alternatives:
7...Qh4 8.Qf3+ Ke8 9.Nc3 Ne7 (9...Bxf2+ 10.Qxf2 Qxf2+ 11.Kxf2 Nh6 12.Nd5 Ng4+ 13.Kg3 Kd8 14.Bg5+ Nf6 15.exf6 h6 16.fxg7+ Ke8 17.gxh8=Q+ Kf7 18.Rhf1+ Kg6 19.Qxh6 checkmate, Wall,B - Shillam, lichess.org, 2016) 10.g3 Qh3 11.Be3 d6 12.Bxb6 cxb6 13.exd6 Ng6 14.Nd5 Qd7 15.Nc7+ Kd8 16.Nxa8 Qxd6 17.Rd1 Ne5 18.Rxd6+ Ke7 19.Qc3 Kxd6 20.Qd4+ Ke6 21.Nc7+ Kf7 22.Qxe5 Rd8 23.Nb5 Bg4 24.Qf4+ Kg8 25.Qxg4 a6 26.Qe6+ Kh8 27.Nd6 Rb8 28.Nf7+ Kg8 29.Nh6+ Kh8 30.Qg8+ Rxg8 31.Nf7 checkmate, Wall,B - Itboss, lichess.org, 2016;
7...Qe7 8.Qf3+ Ke8 9.Nc3 Qxe5 10.O-O Nf6 11.Bf4 Qh5 12.Qg3 d6 13.Qxg7 Rf8 14.Nd5 Qf7 15.Bh6 Nxd5 16.Qxf8+ Qxf8 17.Bxf8 Kxf8 18.exd5 Bf5 19.c3 Re8 20.Rfe1 Be4 21.Rad1 Kf7 22.Kf1 Re5 23.f3 Bg6 24.Rxe5 dxe5 25.Ke2 e4 26.b4 exf3+ 27.Kxf3 Bh5+ 28.g4 Bg6 29.c4 a6 30.d6 cxd6 31.Rxd6 Bb1 32.Rxb6 Bxa2 33.Rxb7+ Ke6 34.Rb6+ Kd7 35.c5 Black resigned, Wall,B - NN, lichess.org, 2016.
8.O-O Be6 9.Qf3+ Ke8 10.Nc3 a6 11.Be3 dxe5
For now White has only one pawn for his sacrificed piece, but Black's uneasy King comes close to making up the rest of the compensation.
12.Qh5+ Bf7 13.Qxe5+ Qe7 14.Qxg7 Qf6
15.Bh6 Bd4 16.e5 Qg6
This move allows White's pieces to become troublesome - enough so that Stockfish 8 suggests instead that Black give back the exchange with 16...Qxh6 17.Qxh8 Rd8 and then exchange some more pieces, e.g. 18.Ne4 Qg6 19.c3 Qxe4 20.cxd4 Bd5 21.Qg7 Ne7 22.Rfe1 Qg6 23.Qxg6+ hxg6 where White only has an edge.
17.Qf8+ Kd7 18. Qxa8 Qxh6
Black returns the exchange in his own way. The difference is that he is not now as equipped to protect his King.
19.Rfd1 c5 20.Qxb7+ Ke8 21.Qb8+ Ke7 22.Ne2 Bh5
23.Nxd4 Bxd1
A final slip.
24.Nf5+ Black resigned
