1.e4 c5 2.Nf3 d6 3.Bb5+ Nd7 4.d4
        It is best to play this right away, as 4 O-O Nf6 5 Re1 e5! does not generate much. Instead, White needs to utilize Black's temporary bottleneck.
Ngf6 5.Nc3
        On 5 e5 Nd5 (better than the immediate 5 ... Qa5+ 6 Nc3 Ne4 7 Bd2), White is slowed down by the threat of Qa5+. But the real reason that Black played 4 ... Ngf6 is to avoid the sharper variation 4 ... cxd4 5 Qxd4 Nf6 6 Bg5, when 6 ... e7-e5 would create too much of a hole on d5 (White can still play c2-c4) so he would have to settle for the more passive 6 ... e7-e6.
... cxd4
        This is the main line. the move 5 ... a6, challenging White's strategy and picking up the two bishops at the cost of development, should leave White with a pull after 6 Bxd7+ Nxd7 7 O-O e6 8 Bg5.
6.Qxd4 e5
        On 6 ... e6, White can change the nature of the proceedings with 7 Bg5 Be7 8 O-O-O!? O-O 9 h4 with what looks like a favorable type of Richter-Rauzer setup. And on 6 ... g6, the accepted treatment is 7 Bg5 Bg7 8 O-O-O O-O 9 e5! dxe5 10 Nxe5 Qa5 11 Nc4 as in Stean - Dueball, 1974.
7.Qd3 h6
        There is too much pressure on the d-file to allow the pin. Here 7 ... Be7 8 Bg5 O-O 9 Bxd7 Qxd7 10 Bxf6 is very nice for White.
8.Be3
        This natural development is better than 8 Nd2 Be7 9 Nc4 O-O 10 Bxd7 Bxd7! 11 O-O (if 11 Nxd6 Qc7 12 Nf5 Bxf5 13 exf5 e4 with dynamic play for Black in Mednis - Csom, Cleveland 1975) Be6 12 Ne3 Rc8 with no problems in Verber - Kavalek, USA 1976.
Be7 9.Bc4 a6 10.a4
        It is necessary to stop any Black expansion with ... b7-b5.
10. ... Qc7
        This liberation plan is better than 10 ... Ng4 which only effects the minor piece exchange that Black was preventing with his ... h7-h6. Also, 10 ... O-O 11 O-O Nb6 12 Bb3 Be6 is a possibility, but then 13 Nh4 is annoying, focussing on f5 and potentially g6. In R. Antonio - L. Chiong, Quezon City 1999, Black chose 10...0-0 11.0-0 Qc7 12.a5 Nc5 13.Bxc5 Qxc5 14.Nd5 Nxd5 15.Bxd5 Be6 16.Bxe6 fxe6 17.Qb3 Qc8 18.Rfd1 Rf6 19.Ra4 Qc6 20.Rc4 Qb5 21.Rb4 Qxa5 22.Rxb7 Bf8 23.Qc4 Re8 24.h3 Rf7 25.Qc6.
11.0-0 Nc5
        On 11 ... O-O, White might radically prevent this move with 12 b4! and then after 12 ... Nb6 13 Bb3 Be6 14 Nd5, White is developing a real queenside initiative.
12.Bxc5 Qxc5 13.Rab1
        This appears to be a new move. In the game Yudasin - Kozul, Pula 1997, White did not achieve the desired effect with 13.Nd5 Nxd5 14.Bxd5 0-0 15.Ra3 Rb8 16.Rd1 Kh8 17.Rc3 Qa5 18.Qc4 f5 19.b4 Qxa4 20.Qc7 Bd7 21.Bb3 Qb5 22.Bc4 Qxb4 23.Rb3 Qa4 24.Rxb7 Rxb7 25.Qxb7 Qxc2 26.Re1 Qxc4 27.Qxd7 Bf6.
13...Be6
        This is indicated because otherwise, White will follow up with b2-b4 and then Nc3-d5, retaking with his bishop on d5 to clear the way for a c-pawn advance.
14.Nd2 Rc8 15.Bxe6 fxe6 16.Qh3
        With Black having dealt with the c-file issue, White's only chance for the initiative is to inconvenience the Black king.
Kf7 17.Nb3 Qc7 18.Kh1
DIAGRAM
18. ... g5
        A defensive advance. Gallagher figured that his king is stuck on f7 for the foreseeable future to defend the e6 pawn; therefore, stopping an f-file opening is paramount.
19.Rbd1 h5
        Forming a pawn duo. The presence of the pawn on g5 naturally draws its brother up even with it.
20.Qd3 Qb6 21.Qe2 Qb4 22.Rd3 b5 23.axb5 axb5 24.h4 g4 25.f4 Qc4 26.Nd2 Qc5 27.f5 b4 28.fxe6+ Kxe6 29.Nd5 Nxd5 30.exd5+ Kd7 31.c3 Rhf8 32.Ne4 Qc4 33.Ra1 bxc3 34.bxc3 Ra8 35.Rb1 Ra2 36.Qe3 Rf4 37.Ng3 Qa6 38.Nxh5 Ra1 39.Rxa1 Qxa1+ 40.Kh2 g3+ 41.Kxg3 Bxh4+ 42.Kh2 Bf2 43.Qxf4 exf4 44.Nxf4 Qg1+ 45.Kh3 Be3 46.Ne2 Qh1+ 47.Kg3 Qe1+ 48.Kf3 Qf2+ 49.Ke4 Bh6