Theory on Non-Theory

Even in the non-main-line lines of the non-main-line Jerome Gambit, there is theory, and practice, as Philidor1792 demonstrates in the game below.

Philidor1792 - jenskun
Russia Central Federal District vs Phil, 
Chess.com, 2015

1.e4 e5 2. Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ Kxf7 

5.Nxe5+ Nxe5 6.Qh5+ Ng6 7.Qd5+ Ke7 

Infrequently played, but not bad.

8. Qxc5+

The experimental 8.Qg5+ was tried in Wall,B - CKFM, FICS, 2012 (1-0, 44). 

8... d6 9. Qe3 

The Database has three games with 9.Qg5+: fehim - Schiele, FICS, 2006, (0-1, 59); stampyshortlegs - calchess10, JGTourney4, ChessWorld 2009 (1-0, 31); and Wall,B - Vassilev,R, Chess.com, 2010 (1-0, 32).

9... Be6

Instead, 9... Nf6 was seen in three MrJoker games:  MrJoker - Yuvi, ICC, 2011 (1-0, 16); MrJoker - Cleanbishop, ICC, 2012 (1-0, 46); and MrJoker - taz, ICC, 2013 (1-0, 43).

The Bishop move seems to invite f2-f4 by White, gaining a tempo.

10.O-O Nf6 11.f4 Bf7 12.f5 Ne5 13.d4 Nc6 14.e5 dxe5 15.dxe5 Nd5 16.Qg3 Kf8 

The extra tempo for White, the "Jerome pawns" and Black's uneasy King have lead to an equal game. As we have frequently seen in Jerome Gambit lore, when White has equalized, he has the advantage.

17.Bg5 Qc8 18.e6 Bh5 19.Nc3 Nxc3 20.Qxc3 Rg8 21.f6 gxf6 22.Qxf6+ Ke8 23.Rad1 Qd8 24.Rxd8+ Rxd8 25.b4 b5 26.a4 a6 27.axb5 Black resigned