1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0–0 Be7 6.Re1 b5 7.Bb3 0–0 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 Bb7 12.d4
This is the established mainline and seems to force Black to look for long-term compensation for his pawn rather than the quick kingside attacks which sometimes results from the 11...c6 lines.
This may transpose to 12...Bf6 lines but must primarily be considered an attempt to play for a kingside attack.
a) 12...Bf6, the mainline to which I will some day return superficially appears less attractive as it generally is associated with a queenside initiative.
b) 12...Nf6!? is suggested by Eric J and gets an additional improvement by Benjamin. Surprisingly no mention is made of the transposition 11...Nf6 (Marshall's original attempt) 12.d4 (White's clearly most popular reaction) 12...Bb7!? (12...Bd6 is almost exclusively played) which leads to the same position without allowing 11.Qf3.
a) 13.Qh5 Nf6 14.Qf5 Qxf5 15.Rxf5 Be4 16.Rg5 Bd6 17.f4 Rfe8 18.Nd2 Bb7 19.Nf1 Re1 20.Kf2 Rxc1 0–1 Gardner-Harding, corr 1975.
b) 13.h3 looks like a waste of time:
b1) 13...Bf6 seems somewhat inconsistent but sufficient for equality: 14.Re1 Rfe8 15.Bd2 Rxe1+ 16.Qxe1 Re8 17.Qf1 Ne7 18.Na3 c5 19.Rd1 cxd4 20.Be3 Nf5 21.Bxd4 Nxd4 22.cxd4 g6 23.Nc2 a5 = Krnan-Tseitlin, Montreal 2004.
b2) 13...Rfe8 14.Nd2 Bf6 15.Rxe8+ Rxe8 16.Nf3 Qd6 17.Bd2 c5 18.dxc5 Qxc5 19.Qc2 Re2 20.Be3 Rxc2 21.Bxc5 Re2?? (21...Rxb2 =) 22.Rd1+- Granada Velez-Hakimifard, Kemer 2007.
c) 13.Qf3 Rad8 looks like the principal alternative:
c1) 14.Nd2 c5 and now:
c11) 15.Qf5 Bf6 16.Qxd7 Rxd7 17.Re1 cxd4 18.Ne4 dxc3 19.Bxd5 Bxd5 20.Nxf6+ gxf6 21.bxc3 ½–½ Pieris-Sarfati, Dubai 1986.
c12) 15.dxc5 Bf6 16.Re1 Nxc3 17.Qg3 Na4 (17...Rfe8 18.Rxe8+ Qxe8 19.bxc3 Bxc3 20.Rb1 Bxd2 21.Bxd2 Rxd2 = Boguslavsky-Ketterer, Karlsruhe 2003) 18.Bxa4 bxa4 19.Nc4 Qd5 20.Nb6 Qxc5 21.Nxa4 Qc6 22.Nc3 Bh4 23.Qh3 Rd6 24.Bf4 Rf6 25.Ne2 g5 26.Bg3? (26.Rac1 Qb6 =+) 26...Bc8 0–1 Dimitrov-Hebden, Cappelle la Grande 1989.
c2) 14.Qf5 Qxf5 15.Rxf5 Bf6 (15...Rfe8 16.Be3 g6 17.Re5 f6 18.Re4 Kg7 19.Bd2 c5 20.Na3 Nc7 21.Re2 cxd4 22.Rae1 Bf8 23.Rxe8 Nxe8 = Harley-Hebden, Hastings 1988) 16.Bg5 Rfe8 17.Kf1 Bxg5 18.Rxg5 Nf4? (18...h6 or 18...Re7 look quite playable) 19.Bxf7+ Kxf7 20.Rf5+ Kg8 21.Rxf4 +/- Mihailov-O.Moen, Trondheim 2004.
13...Bf6 still looks inconsistent but didn't work out too badly in Traut-Diaz Vega, corr 2002: 14.Re1 Rae8 15.Rxe8 Rxe8 16.Nf3 Qf5 17.Bc2 Qh5 18.Bd2 += .
This was Black's idea but it doesn't seem very tempting when White simply can capture the bishop. However, the knight on f4 is hanging so there are not many alternatives:
a) 14...Ng6 15.Nc5 Bxc5 16.Rxc5 Rae8 17.Be3 Kh8 18.Rh5 Be4 19.h3 Ne7 20.Re5 +/-Rogers-Djuric, San Bernardino 1988.
b) Benjamin mentions that 14...Nxg2 15.Kxg2 Bf6 16.Qf3 seems insufficient.
15.Nxd6 cxd6 16.Rg5 Ng6 (Dia)
Benjamin only gives this move and concludes that White is better. 17.Be3 seems at least as strong. Henao-Djuric, Saint John 1988 continued 17...Rae8 18.a4 Be4 19.axb5 axb5 20.Bc2 d5 21.Bxe4 Rxe4 22.Qc2 f5 23.g3 += but it's easier for White to improve than for Black. One relatively obvious try is 20.Qh5.
17...Rae8 18.Bg5 Qf5
Or 18...Be4 19.h4 d5 20.h5 Ne7 21.Bh6 Nf5 22.Qg4 g6 1–0 Conquest-Lane, Cappelle la Grande 1990.
19.Bc2 Be4 20.Bxe4 Rxe4 21.a4 bxa4 22.Rxa4 +/- Kudrin-Hebden, Las Palmas 1989.
12...Qd7 doesn't seem sufficient to turn 11...Bb7 into an attacking line and Black may as well admit that with 12...Bf6.