Breunor: I'm with Goodevans, good pun, game a bit silly.On 18, Stockfish agrees with the game move:
1) -6.11 (33 ply) 18...Qb4+ 19.Rc3 Qxg4 20.O-O Rad8 21.Qc4 Qg6 22.Nh4 Qh5 23.Nf3 Ne5 24.Nxe5 Rxe5 25.f3 Rd2 26.Rd3 Rxb2 27.Qc3 Rxa2 28.Rd8+ Kh7 29.Rd2 Rxd2 30.Qxd2 Rc5 31.e4 a5 32.Qa2 Qg6 33.h3 Rc3 34.Qd2 Ra3 35.Kh1 b5 36.Rd1 b4 37.Rb1 Qe6
Rad8 doesn't win:
1) -0.43 (21 ply) 19.Qb5 Nb4 20.O-O Ba6 21.Qa4 Be2 22.Bf5 g6 23.Bb1 Bxf1 24.Rxf1 Nd3 25.a3 Ne5 26.Nd4 Kg7 27.Ba2 Rd7 28.Bb1 Rc8 29.Rd1 Rdc7 30.Qb3 Rc1 31.f4 Rxd1+ 32.Qxd1
On move 20, once again Stockfish agrees with the game move but Rad8 has about the same score:
After 20 B x c6:
1) -7.77 (36 ply) 21.Qxc6 Rec8 22.Qf3 Rc1+ 23.Ke2 Qxf3+ 24.Nxf3 Rxh1 25.Ne1 Kf8 26.Nd3 Rc8 27.Kd2 Ke7 28.e4 g5 29.h4 Rc4 30.hxg5 hxg5 31.Ne5 Rc8 32.Nd3 Rg1 33.a4 Ke6 34.a5 b5 35.Ke3 Rc2 36.f4 Rgxg2 37.f5+ Kf6 38.Kf3 Rxb2 39.Nxb2 Rxb2 40.e5+ Kxe5 41.Kg4 f6 42.a6 Rb4+ 43.Kg3 Kxf5
If 20 Rad8
1) -7.13 (24 ply) 21.Rc4 Qg6 22.Qxb7 Qd3 23.Rc2 Qxc2 24.O-O Rxd2 25.h3 Qa4 26.a3 Rxb2 27.Ra1 Rd8 28.Qe7 Rbd2 29.Qe5 Rd1+ 30.Kh2 Rxa1 31.Qxa1 Rd1 32.Qc3 Qb5 33.a4 Qf5 34.Kg3
Although 18 Qxd5 is clearly the losing move, white is already considered down a bit. Best line is:
1) -0.78 (34 ply) 18.Qa4 Rad8 19.O-O Qe4 20.Qxe4 dxe4 21.Nh4 g6 22.Rc2 Rd6 23.Rfc1 Red8 24.h3 a5 25.a3 Ne5 26.Be2 Kg7 27.b4 Nd3 28.Rb1 axb4 29.axb4 R6d7 30.g3 Ne5 31.Rbc1 Rd2 32.b5 R8d5 33.Ng2 Nf3+ 34.Kh1 g5 35.Rxd2 Rxd2
White appears to go off the best track with 15 Bg4.
Best is 15 dxc5:
1) +0.59 (32 ply) 15.dxc5 bxc5 16.O-O Ba6 17.Bxa6 Nxa6 18.Rfd1 Qd6 19.Nd3 Rac8 20.a3 Rfd8 21.Nf4 d4 22.Qc4 Rb8 23.b4 cxb4 24.Rxd4 Qc5 25.Qxc5 Nxc5 26.Rxd8+ Rxd8 27.axb4 Na6 28.b5 Nc7 29.Kf1 Nxb5 30.Rc5 Nd6 31.Ra5 Ne4 32.Nd5 Kf8 33.Ke1 Nd6 34.Nc7 Nc8 35.Ra6 Rd6 36.Ra5 Ne7 37.Rxa7 Rb6 38.Ke2 Rb2+ 39.Kf3
But after 15 Bg4 black is ahead:
1) -0.46 (36 ply) 15...cxd4 16.Qxd4 Re8 17.f4 Nc6 18.Nxc6 Qh4+ 19.g3 Qxg4 20.O-O Bxc6 21.Rxc6 Rad8 22.Rc3 h5 23.Qd1 Qf5 24.Rd3 h4 25.gxh4 Qg6+ 26.Kh1 Qe4+ 27.Kg1 Rc8 28.Qd2 Rc6 29.f5 Qxh4 30.Rxd5 Rec8 31.Qf2 Qf6 32.Rd2 Rc1 33.Qf4 R1c2 34.Rxc2 Rxc2 35.Rf2 Qxb2 36.Rxc2 Qb1+ 37.Qf1