Twyble-Gayson
Barbican 2 vs White Rose
Annotations by GM John Emms

1 d4 f5 2 Nf3 Nf6 3 g3 g6 4 Bg2 Bg7 5 c4 d6 6 0-0 0-0 7 Nc3 Qe8 8 d5 Na6 9 Rb1 Nc5 10 b4
10 Nd4 a5 11 b3 Bd7 12 Ba3 c6 was equal in Mohr-Vasiukov, Voskresensk 1990. ]
10 ..Nce4 11 Bb2
According to Belov, White can obtain a small edge with 11 Nxe4! for example 11 ..Nxe4 12 Bb2 Bxb2 13 Rxb2 e5 14 dxe6 Bxe6 15 Nd2 Nxd2 16 Qxd2 Bxc4 17 Bxb7 Rb8 18 Rc1 Rxb7 19 Rxc4 and Black has the slightly weaker pawn structure (3 pawn islands against 2).
11 ..e5 12 dxe6 Bxe6 13 Nd2
13 Nxe4 fxe4 14 Nd2 Bf5 15 e3 Qe6 was equal in the game Akopian-Vasiukov, St Petersburg 1994.]
13 ..Nxd2 14 Qxd2 Bxc4!
In his notes to the Akopian-Vasiukov game, Belov only gives the continuation 14 ..c6 15 b5 Rc8, which he assesses as unclear. Gayson's natural capture of the c-pawn looks to be stronger.
15 Bxb7 Rb8 16 Bg2 Rxb4
Now White is struggling to justify being a pawn down.
17 Nd5 Nxd5 18 Bxd5+
18 Bxg7 may be stronger. After 18 ..Rxb1 19 Rxb1 Kxg7 20 Qd4+ Nf6 21 Qxc4 it will be difficult for Black to exploit his extra pawn.
18 ..Bxd5 19 Qxb4
Or 19 Qxd5+ Qf7 20 Qxf7+ Rxf7 21 Bxg7 Rxb1 22 Rxb1 Kxg7 and Black remains a pawn to the good in the ending.
19 ..Qxe2
Threatening the deadly ...Qf3.
20 Qa3 Rb8! 21 Bxg7 Rxb1 22 Rxb1 Qe4
Despite being temporarily a rook up, White is totally lost.
23 Rb8+ Kf7! 24 f3 Qe1+ 25 Kg2 Qe2+ 26 Kh3 Bxf3 0-1
White has to give up the queen to avoid a quick mate.