Jerome Gambit: Balanced Until Unbalanced

The Jerome Gambit is often presented as some kind of bashi-bazouk attack, referring to, according to the Encyclopedia Britannica, "mercenary soldier[s] belonging to the skirmishing or irregular troops of the Ottoman Empire, notorious for their indiscipline, plundering, and brutality."

Yet some Jerome games move along placidly, largely balanced, with White content to develop his pieces and advance his "Jerome pawns" - until. A sudden imbalance brings a sudden end. 

Wall, Bill -Guest5296006
PlayChess.com, 2018

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bxd4 7.Qxd4 Qf6 

A move that has the threat of either winning or exchanging the enemy Queen. White notices, but doesn't seem to mind.

8.Be3 Ne7 9.O-O Rf8 10.Nc3 c6 11.Rad1 Kg8

Black has castled-by-hand, and has a piece for a pawn. If this distresses his opponent, it is not apparent.

12.f4 Ng4 13.Qxf6 Nxf6 14.Bc5 Re8 15.Bd6

Black's Bishop is at home, currently blocked in - and it, in turn, blocks his Rook (a dilemma we have seen many times before). His solution is to advance the Queenside pawns, which drains away his advantage.

15...b5 16.f5 a5 17.e5 

In the meantime, White moves in the center. The position is about even.

I am reminded of something GM Andy Soltis wrote in Grandmaster Secrets Openings (2000), that at some point a player has to decide if he is going to go for a small advantage, or a large advantage. Black can keep things balanced, here -but he wants more.

17...Nfd5 

He should have relied on 17...Ned5 18.exf6 Nxf6.

18.f6 

At first, a bit of a surprse, as Black is threatening the Knight fork of two Rooks with 18...Ne3, but White can meet this with 19.f7+ Kf8 20.Ne4!? giving up the exchange, as 20...Nxf1 21.Rxf1 requires that Black return the Rook, with 21...h6 22.fxe8/Q+, because 21...Rd8 22.Ng5 would be even worse. 

18...gxf6 19.exf6 

Now Black can try to struggle on after returning the Knight with 19...Nxf6 20.Rxf6, possibly reaching a Bishops-of-opposite-colors endgame, but he thinks he can do better. He can't.

19...Nxc3 20.f7+ Kf8 21.bxc3 

You know that White's game is powerful when he doesn't have to capture the Rook at e8, 

21...Rd8 22.Rde1 Black resigned

Not only does White threaten to win the Knight at e7, with check, then pick up the Rook at d8, he also has a forced checkmate, e.g. 22...Kg7 23.Rxe7 Rf8 (What else?) 24.Re3 h6 25.Bxf8+ Kxf8 26.Re8+ Kf7 27.f8/Q+ Kg6 28.Qf5+ Kg7 29.Qf7#