The following game shows a classic Jerome Gambit matchup between Black's pieces and White's pawns. The defender is doing fine in diagram 3, but quickly destroys his chances with his 9th move. This is a familiar tale: Black needs to be wary if he is unfamiliar with the Jerome.
Wall, Bill - Pelk
1.e4 e5 2.Nf3 Nc6 3.Bc4 h6
The Semi-Italian opening.
4.Nc3 Nf6 5.O-O Bc5 6.Bxf7+
The Semi-Italian Four Knights Jerome Gambit.
6...Kxf7 7.Nxe5+ Nxe5 8.d4 Bd6 9.f4
White adds another "Jerome pawn" to the center picture. Of course, he could also have played 9.dxe5 Bxe5 10.f4.
What to do? What to do? What to do? Black would be doing fine after the retreat 9...Nc6. He is, after all, ahead two pieces. Instead, his bold move blows up the position.
10.fxe5+ Nf6 11.Nd5 Be7
Black admits that he will have to give back a second piece. Perhaps he overlooks that there is already a forced checkmate. (Admittedly, it is a mate-in-14, but it is not difficult to work out.)
12.exf6 Bxf6 13.Qh5+ Kg8 14.Nxf6+ gxf6 15.Qg6+ Kf8 16.Rxf6+ Black resigned