De Arman's 1893 Guide to the Chess Openings notes "The Jerome Gambit... is of course strictly unsound, as the sacrifice of a piece thus early in the game must ever be..." but, nonetheless, calls it "a very hazardous but interesting attack." True, an unfortunate slip early on can take Black down a slippery slope.
perrypawnpusher - louarn
blitz, FICS, 2010
1.e4 e5 2.Nf3 Nf6 3.Nc3 Nc6 4.Bc4 h6 5.0-0 Bc5
Transposing, at last, to the Semi-Italian Four Knights Game.
6.Bxf7+ Kxf7 7.Nxe5+ Nxe5 8.d4
8...Bxd4
Our earlier game continued 8...Re8 9.dxc5 d6 10.cxd6 Qxd6 11.Qe2 Bg4 12.f3 Bh5 perrypawnpusher - louarn, blitz, FICS, 2010. After an exchange of errors I escaped into a won endgame (1-0, 49).
9.Qxd4 Qe7 10.f4 c5
A slip: I attack Black's Knight with a pawn (more effective than with a Bishop, as in perrypawnpusher - philippeemuuma, blitz, FICS, 2010, 1-0, 28) so he reflexively attacks a bigger piece, my Queen.
The correct move, as in perrypawnpusher - kinghh, blitz, FICS, 2010, was 10...Nc6, (1-0, 31)
11.Qxe5 Qxe5
Worse than 11...Re8, as seen in perrypawnpusher - jaymen, blitz, FICS, 2010 (1-0, 40)
12.fxe5 Ke6
There's no stopping the slide now, although 12...b6 13.exf6 g5 would have slowed it a bit.
13.exf6 Rf8 14.fxg7 Rg8
15.Bxh6 d6 16.Rf8 Bd7 17.Raf1 Ke5
18.Rxa8 Rxa8 19.Rf8 Rxf8 20.gxf8Q Be6 21.Bg7 checkmate