Jerome Gambit: Just. Don't.

Black has many defenses to the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+), some focused on returning one of the two gambitted pieces. In the following game, Bill Wall faces one that he has encountered - and defeated - 20 times previously. I suspect his advice to his opponent would be: Just. Don't.

Wall, Bill - NN
Florida, 2019

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bd6 

Not the best defense: the game is already even, according to Stockfish 10, even though Black is two pieces ahead.

7.dxe5 Bxe5

This move is a troublesome companion to the previous one, shifting the evaluation of the game to White's favor. According to The Database, out of 160 games, Black played this move 139 times.

8.Qd5+

The proper response.

8...Kf6

He is not going to be able to save the Bishop, but retreating the King is not much better.

9.f4 c6 

10.fxe5+

An improvement over 10.Qxe5+, which still won for White in Wall,B - Neilson,C, Melbourne, FL 2016, (1-0, 24). 

10... Ke7 11.Qd3 Qa5+ 12.Nc3 Qxe5 

Material is even, but development and King safety are not. 

13.O-O h6 

Keeping White's Bishop off of g5, but hastening the end.

14.Bf4 Qc5+ 15.Be3 Qh5 16.e5 Ke8 17.Ne4 Ne7 18.Nd6+
Kd8 19.Nf7+ Black resigned

Nice.

Jerome Gambit: Disease 1, Cure 0

If you are playing Black, and you are surprised by your opponent, it is tempting to try and fix the problem by, in turn, unleashing your own surprise. This is often risky, however, as it is not at all clear that you will not get deeper into trouble.

Wall, Bill - Guest753529
PlayChess.com, 2019

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Ke8 

The major problem with this move is that it leads to a position that Black is not prepared to deal with. He may have planned to "take White out of his book" by refusing to play the "normal" 5...Nxe5, but this is one of the cases where the "cure" is worse than the "disease".

6.Nxc6 dxc6

Instead, 6...bxc6 7.Qh5+ g6 8.Qxc5 Ne7 9.Qc3 Black resigned, Wall, Bill -Qwerty, PlayChess.com, 2010.

Best is still the unplayed 6...Qh4!? 

7.Qh5+ Kd7 

Bill has also faced 7...Kf8 in Wall, Bill - Gebba, Chess.com, 2010 (1-0, 11) and Wall, Bill - Guest8678247, PlayChess.com, 2019 (1-0, 24); as well as 7...g6 in Wall, Bill - Tedah, lichess.com, 2016 (1-0, 13) and Wall, Bill - Guest2781227, PlayChess.com, 2018 (1-0, 18). 

8.Qxc5 Nf6 9.d3 b6 10.Qg5 Qe7 11.O-O Ba6 12.Nc3 h6 

Black pushes back, but he is a couple of pawns down, and White has too much play.

13.Qf5+ Kd8 14.Be3 Rf8 15.f4 Nd5 

At first glance, this looks scarier than it actually is. White has an effective response.

16.Nxd5 Rxf5 17.Nxe7 Kxe7 18.exf5 Black resigned

White is now two pawns and a Rook better.

Jerome Gambit: Lost In The Weeds

The following Jerome Gambit game is another example of a defender doing well, objectively, until he gets lost in the weeds, off the beaten path...

Wall, Bill - Guest4241
ChessTempo, 2019

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Bxf7+ 

4...Kxf7 5. Nxe5+ Nxe5 6. d4 Bxd4 

Simple and straight forward.

7.Qxd4 Qf6 

Funny: the threat is 8...Nf3+, winning White's Queen. It is as old as Jerome - Norton, correspondence, 1876 (unfinished). The move is no surprise, though, to Bill: he has faced it 20 times.

8.Nd2 d6 9.O-O Ne7 10.f4 N5c6 

Black is doing well. He needs a plan. The plan should be based on the needs of the position. White should mess with all that assessment and calculation.

11.Qc4+ 

This is something new, according to The Database. Sometimes, Bill likes to take the game even further off the beaten path.

11...Be6 12.Qb5 Qd4+ 13.Rf2 b6 

Just the kind of thing that White has been looking for.

Of course, Black could have played 13...Qb6, protecting his b-pawn and offering to exchange Queens, but he probably skipped that line because he saw himself as being on the attack, so having his Queen would be valuable. (Besides, White would have responded with 14.Qe2.)

The thing is, Black's b-pawn is not really in danger, as 13...a6 14.Qxb7? Ra7 would show. A more measured response by White would still show that Black is better: 14.Qe2 Kg8 15.Nf3 Qf6.

14.Nf3 Qxe4 

Throwing the game away. It is humorous to see that Stockfish 10 recommends as best, instead, the Queen swap 14...Qc4 15.Qxc4 Bxc4 - something Black has been avoiding.

15.Ng5+ Kg6 16.Nxe4 Black resigned