I recently updated The Database with games from the Free Internet Chess Server, through the end of 2019. The 62,000 games therin represent the largest collection of Jerome Gambit and Jerome-ish openings that I know of.
In addition, because 90+% of the games come from online club play (wins, losses and draws), they are pretty representative of the practical outcome of certain moves or lines. Players can consult their favorite computer (Stockfish, Komodo, Houdini, Crafty, etc.) to get an "objective" assessment of play, and then they can dip into The Database and see how well the lines have fared in play.
There are 15,036 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+, the main line Jerome Gambit.
There are 2,715 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Bc5 5.Bxf7+, the Italian Four Knights Jerome Gambit.
There are 207 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.0-0 Bc5 5.Bxf7+ and 160 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.Nc3 Bc5 5.Bxf7+, both variants of the Semi-Italian Jerome Gambit.
There are 148 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.Nc3 Nf6 5.0-0 Bc5 6.Bxf7+, the Semi-Italian Four Knights Jerome Gambit.
There are 6,388 games with the moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4 4.Bxf7+, The Blackburne Shilling Jerome Gambit.
There are 2,470 games with the declination 1.e4 e5 2.Nf3 Nc6 3.Bc4 Na5.
There are 17,582 games with the moves 1.e4 e5 2.Bc4 Bc5 3.Bxf7+, the Abrahams Jerome Gambit.
That leaves about 17,500 miscellaneous games that are Jerome-related, primarily through an early Bxf7+. They are there both to give players ideas about the opening - an for entertainment purposes.
The following game is another example of Black defending well, only to relax too early - and feel the sharpness of White's attack.
angelcamina - tbena
1 0 bullet, lichess.org, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Bc5 5.Bxf7+
The Italian Four Knights Jerome Gambit.
5...Kxf7 6.Nxe5+ Nxe5 7.d4 Bxd4 8.Qxd4 d6
9.O-O Bd7 10.f4
One of the weapons in the Jerome Gambiteer's arsenal.
10...Nc6 11.Qc4+ Be6 12.Qe2 Re8 13.f5
An annoying "Jerome pawn" move, another weapon.
13...Bc8 14.Qc4+ Kf8
15.Bg5
Ditto.
15...Ne5 16.Qb3 b6 17.Nd5
And, again.
17...Bb7
Black completes his development, and wonders "Have you got anything left?" White shows that he does.
18.Nxf6 gxf6 19.Bh6+ Ke7 20.Qe6 checkmate
Very pretty.
The following game features an early slip by Black which surrenders his advantage. It is instructive, however, to see how White builds his attack, culminating in checkmate.
Wall, Bill - Guest6179121
PlayChess.com, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 7.f4 Nf6
Black is unfamiliar with the Jerome Gambit. In addition, my guess is that this is a blitz game, and that Black did a rapid "calculation" - I have 3 pieces developed to 1 of his, and I attack his Queen!
8.Qxe5+ Kf7 9.Qxc5 d6 10.Qb5 a6
The loss of a tempo increases the danger.
11.Qb3+
Raising the question (which takes time to answer) - can White afford to grab the b-pawn after 11...Be6? It is likely not worth the effort: 11...Be6 12.Qxb7 Qd7 13.Qb4 c5 14.Qa3 Nxe4. Still, Black declines to make the offer.
11...Kf8 12.e5 dxe5 13.fxe5 Nd5 14.O-O+ Ke8
15.Nc3 c6
Black does not fall for 15...Nxc3 16.Qf7#
16.Ne4 Rf8 17.Nd6+ Kd7 18.Rxf8 Qxf8
19.d4 Kc7 20.Bg5 h6 21.Rf1 Qg8 22.Rf7+ Kb8 23.Rxb7+ Bxb7 24.Qxb7 checkmate
Ouch.
In the following game, Black's initial moves give him good play. He relaxes too soon, however, and finds danger along the f-file - twice.
Wall, Bill - Guest2056949
PlayChess.com, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4
6...Bxd4 7.Qxd4 Qf6 8.Be3 Ng4
Give Black extra points for creativity. There is only one other game in The Database with this move - a blitz win for the second player.
9.Qb4 Nxe3 10.fxe3
Stockfish 10 sees Black with a winning game.
10...d6
Ooops.
Won games don't win themselves.
Perhaps the game should have continued 10...Qh4+ 11.g3 Qe7 12.O-O+ Nf6, still good for Black.
11.Rf1 Qxf1+ 12.Kxf1 Nf6 13.Qc4+ Be6 14.Qxc7+ Kg6 15.Qxd6 Rae8
White has a Queen and 3 pawns for a Rook and a Bishop. He can work up an attack on the enemy King, or continue to pick off material.
16.Nc3 Rhf8 17.Kg1 Ng4 18.Nd5 Kf7 19.Rf1+ Nf6 20.e5 Black resigned
The Knight, pinned along the f-file, is done for.
When a defender loses to the Jerome Gambit, it usually happens one of two ways. White either falls upon him like a ton of bricks, or Black defends effectively - until something happens. Sometimes the slip the second player makes seems small, but the punishment can still be harsh.
In the following game, the lines in the notes may appear complicated, but they are the kind that an attacker can enter, knowing that, in the end, he will prevail.
Wall, Bill - Guest2038506
PlayChess.com, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bxd4 7.Qxd4 d6
Black has defended well and has a piece for a pawn. He would do well to take care of his King, castling-by-hand.
8.O-O Nf6 9.Nc3 Re8
The defender continues in his task.
It might be relevant to note, however, that Bill has reached this position 15 times, and has scored 13 - 1 - 1. It is a familiar hunting ground.
10.Bg5 h6
11.Bh4 g5 12.Bg3 Nh5
According to The Database, this move is a novelty. Black casually goes about exchanging a Knight for a Bishop.
13.f4
White strikes with what he has. Things are going to get messy.
13...Nc6 14.fxg5+ Kg6 15.Qd3 Nxg3
Black continues according to his plan, unaware that the situation has changed.
16.Rf6+ Kg7
The first shock is that the pawn at g5 cannot be captured, as it would lead, inexorably to checkmate: 16...Kxg5 17.Qxg3+ Kxf6 18.Nd5+ Kf7 19.Rf1+ Bf5
20.Rxf5+ Ke6 21.Qg4 Qh4 22.Nxc7+ Ke7 23.Nd5+ Kd8 24.Qxh4+ Kd7 25.Rf7+ Re7
26.Rxe7+ Nxe7 27.Qxe7+ Kc6 28.Qc7+ Kb5 29.c4+ Ka4 30.Qd7+ b5 31.Qxb5# White does not have to know the exact sequence; he can find his way down the path, move-by-move.
The second shock is that Black's best defense requires him to sacrfice his Queen immediately: 16...Qxf6 17.gxf6 Nh5 (Black has a Rook, a Bishop and a Knight for a Queen and 2 pawns, but his position is very difficult) 18.Nd5 Ne5 19.Qd4 Bd7
20.Nxc7 Nxf6 21.Qxd6 Rac8 22.Rf1 Rxc7 23.Qxc7 Black still has 3 pieces for his Queen, but White should be able to out-play him.
17.Qxg3 Ne5 18.Nd5
18...c6
Black's best defense was complicated and still inadequate: 18...Bg4 19.Qh4 h5 20.h3 Be6 21.Nf4 (21.Qxh5
Rh8) 21...Bf7 22.g6 Bxg6 (22...Qxf6 23.Nxh5+) 23.Qg5 Kh7 24.Nxg6
Qxf6 25.Qxf6 Nxg6 26.Qf7+ Kh6 27.Qxc7 Re7 28.Qxd6 Rf8 29.Re1 Black's Rook and Knight can not stop White's Queen from nabbing pawns and prevailing.
19.gxh6+ Black resigned
Mate will come the next move.
The Jerome Gambit can be a difficult opening for the defender to figure out. Good moves can look bad, and bad moves can look good. The following game is an example.
Wall, Bill - MLHZ
FICS, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Kf8
6.Nf3
A rare move - The Database has only 1 other example - but Bill likes to experiment...
6...Qe7 7.O-O d6
The e-pawn can be taken, but Black is suspicious.
8.d3 Nf6 9.Nc3 Kf7
Black begins the process of castling-by-hand.
10.Nd5 Nxd5 11.exd5 Nd8
Overly careful. The Knight should go to d4.
12.Re1 Qd7 13.Ng5+ Kg6 14.Re4 h6 15.Rh4
15...Qf5
Coming to the rescue, but falling into a tactical trap.
16.Qh5+ Kf6 17.Rf4 Black resigned
Oh, my!
