I have a great idea: the next time you have the white pieces against Bill Wall, why not play the Jerome Gambit? I mean, he wins overwhelmingly with it, so wouldn't it give you an advantage? And he hardly could be expecting to opening, right?
What could possibly go wrong?
Guest687197 - Wall, Bill
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
A popular line: there are 2,219 games with this in The Database.
On the other hand, White scores only 38%, which is poor, even for the Jerome Gambit.
Perhaps the plan is to fool White...
Of course, 5...exd4 is also playable, as in 6.c3 d6 7.cxd4 Bb4+ 8.Bd2 Bxd2+ 9.Nbxd2 Nf6 10.Qb3+ Ke7 11.O-O Rf8 12.Rfe1 Na5 13.Qa3 Nc6 14.d5 Nb8 15.e5 Kf7 16.exf6 Qxf6 17.Ne4 Qf4 18.Rac1 Na6 19.b4 Bg4
20.b5 Nc5 21.Nxc5 dxc5 22.Re4 Qxe4 23.Ng5+ Black resigned, Wall,B - Anonymous, lichess.com, 2016.
White might have considered 6.c3, e.g. 6...Bb6 (6...Bc5 7.Qd5+
Ke8 8.Qxc5 Qe7 9.Qc4 Nf6 10.O-O d6 11.Be3 Be6 12.Qb5 Qd7 13.Ng5 a6 14.Qxb7 Rb8 15.Qxa6 Ke7 16.Nxe6 Kxe6 17.Qc4+ Ke7 18.a4 Rxb2 19.a5 Ra8 20.a6
Ng4 21.Bg5+ Nf6 22.Nd2 h6 23.Bxf6+ gxf6 24.Nf3 Rb6 25.Nh4 Qe6 26.Nf5+ Kd7
27.Qd3 h5 28.Ne3 Qb3 29.Nd5 Qb5 30.Qh3+ Kd8 31.Qe6 Rbb8 32.Qg8+ Kd7 33.Qf7+ Kd8 34.Qf8+ Kd7 35.Qg7+ Kd8 36.Nxf6 Ne7 37.Qf8+ Qe8 38.Qxe8 checkmate, Wall,B - Guest1366999, Playchess.com, 2011) 7.Qb3+ Kf8 8.Bg5 Qe8 9.O-O
Nf6 10.Nbd2 d6 11.a4 Qe6 12.Qc2 h6 13.Bxf6 Qxf6 14.Nc4 Be6 15.Qe2 a6 16.Nxb6 cxb6 17.Rfd1 Rd8 18.Qe3 Bg4 19.Qxb6 Bxf3 20.gxf3 Qxf3 21.Qxb7 Ne7 22.Re1 Nf5 23.Qb6 Qg4+ 24.Kh1 Qf3+ 25.Kg1 Qg4+ 26.Kh1 Qf3+ drawn, Wall,B - Guest2627909, Playchess.com, 2012
6...exd4 7.O-O Nf6
He could also have considered 9.Qxd4.
10.Nd2 d5 11.c4 Nxc4 12.Rc1 Nxb2 White resigned
White could have continued with his idea 13.Qc2 Nc4 14.Nxc4 dxc4 15.Qxc4+ Qd5 16.Qxc5+ Qxc5 17.Rxc5, destroying much of Black's pawn center; but he would still be down a piece and a pawn.
Alas, no chess opening, even the Jerome Gambit, is a guarantee of victory.