A57: Benko/Volga Gambit
1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.Nc3 d6
[5...g6 6.g3 Bg7 7.Bg2 d6 8.Nf3 axb5 9.Nd2 Ba6 10.0-0 Nbd7 11.Nde4 b4 12.Nxf6+ Nxf6 13.Ne4 Nd7 14.Qc2 Nb6 15.Rd1 0-0 16.Rb1 Bb7 17.Qb3 Ra4 18.Nd2 Qa8 19.a3 Bxd5 20.Bxd5 De la Casa,A-Escofet,J/Luzern 1982/EXT 97-B/0-1]
6.Nf3 g6 7.g3 Bg7 8.Bg2 axb5 Diagram
9.0-0N
[>=9.Nxb5!? would keep White in the game 9...Qa5+ 10.Nc3=]
9...b4-/+
Black gains space
10.Nb1
0-0 11.Re1 Nbd7 12.e4 Ba6 13.Qb3 Qb6
[13...Bb5 14.Nbd2-/+]
14.Nbd2=/+
Rfc8
Black plans c4
15.Nc4 Bxc4 16.Qxc4 Ng4 Diagram
17.Nd2?
[17.Qe2!?= looks like a viable alternative]
17...Nge5
[17...Bd4 18.Rf1 Nde5 19.Qe2-/+]
18.Qc2
[18.Qe2!?=/+ must definitely be considered]
18...c4-/+ 19.Nf3?
[>=19.Rf1-/+]
19...b3-+ 20.Qb1 Diagram
[20.Qe2 bxa2 21.Bh3 Nxf3+ 22.Qxf3 Ne5-+]
20...Nd3
[20...Nxf3+!? and Black can already relax 21.Bxf3 c3 22.axb3-+]
21.Be3
Qb4
[21...Qb7 makes it even easier for Black 22.axb3 Rxa1 23.Qxa1 Bxb2 24.Qb1 Nxe1 25.Nxe1 Qxb3 26.Bf3-+]
22.Bd2?!
instead of fighting back [22.axb3 Rxa1 23.Qxa1 Nxe1 24.Qxe1 Qxe1+ 25.Nxe1 cxb3-+]
22...Qb5
[>=22...Qb7!? keeps an even firmer grip 23.axb3 Rxa1 24.Qxa1 Bxb2 25.Qb1 Nxe1 26.Nxe1 Qxb3 27.Qc2-+]
23.axb3
Rxa1
[23...Nxe1 24.Qxe1 Qxb3 25.Bc3-+]
24.Qxa1
Bxb2 25.Qb1?
[25.bxc4 Qb6 26.c5 Qxc5 27.Qa6 Nxe1 28.Nxe1-+]
25...Nxe1
26.Nxe1 c3
[26...Qxb3 27.Qc2 Ra8 28.Bh3-+]
27.Be3 Qxb3 28.Nc2 Ra8 Diagram
29.Bf1
[29.Bg5 doesn't change the outcome of the game 29...Ne5 30.h4 e6-+]
29...Ne5 30.Kg2
Nc4 31.Bxc4
[31.Bd3 doesn't do any good 31...Nxe3+ 32.fxe3 Kg7-+]
31...Qxc4 32.Bc1
[32.Qd1 what else? 32...Qxe4+ 33.f3-+]
32...Qxe4+
33.f3 Qe2+
[33...Qe2+ 34.Kg1 Bxc1-+] 0-1
