Themofro: <Izimbra> No, Bxb4 loses as well, all black moves lose after 17 b4!!,
Here's some analysis of
Onischuk - Shabalov game by John Watson
May 20 2007
The most important game of the tournament thus far ended in a win for last year’s champion Alexander Onischuk. In spite of his tournament standing as the clear frontrunner, a full point and a half ahead, Shabalov was true to his style and played one of the riskiest openings in chess, the Botvinnik System in the Semi-Slav.
<1.d4 d5 2.c4 e6 3.Nc3 c6 4.Nf3 Nf6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7 11.exf6 Qa5!? 12.Be2 Bb7 13.0–0 0–0–0 14.Qc1!?>
14.Bf3, 14.Bf4, and 14.Qc2 have all been tried.
14...Bd6 15.h4 c5!? (15...Qc7 is safer but must be better for White.) 16.dxc5 Bb8! 17.Rd1? Qc7 with a terrific attack was Agdestein-Hector, Reykjavik 1995.
15.dxc5 Bxc5 16.Qf4 Ne5! is a clever move that gives Black reasonable prospects.
<15...cxd4 16.Rxd4 Bc5?>
Amazingly, his natural move comes close to losing directly. 16...Qb6!? has the idea 17.Nxb5 Qxb5 18.Rxc4+ Kb8 19.Rc8+ Rxc8 20.Bxb5.
17...Qc7?! falls short after 18.Bf4 Qc6 (18...e5 19.bxc5 exf4 20.Nxb5) 19.Bf3 Bxd4 (19...Qxf3 20.gxf3 Bxd4 21.Nxb5!) 20.Bxc6 Bxc6 21.a4 Rdg8 22.Bg3 Rxg3 23.hxg3 Ne5 24.axb5 Bb7 (24...Nd3 25.Qa3) 25.Qf4!; Also insufficient is 17...cxb3 18.axb3 Qxa1 19.Qxa1 Bxd4 20.Qc1 Bxc3 21.Qxc3+ Kb8 22.Bxb5; Finally,17...Bxb4 18.Nxb5! Qxb5 19.Rxc4+ Kb8 20.Rb1 is just too strong.
<18.Rb1 Qxb1 19.Qxb1 Bxd4 20.Nxb5 Ne5 21.Bf4>
Black's king is too exposed and he has too much to defend.
<21...Nc6 22.Nd6+ Rxd6 23.Bxd6 c3 24.Bf3 Bb6 25.Bb4 Bd4 26.Bxc3! 1-0>
and Black resigned in view of 26...Bxc3 27.Bxc6 (or 27.Qc2) 27...Bxc6 28.Qc2 Rd8 29.h4.
A game summary:
The line with 11…Qa5 is infrequently played, and the move 14 Qc1! Is an extremely rare move. Possibly Black should play 14…Bd6, although it must give White some advantage. After the natural move 14…c5, Onischuk’s new and unpretentious 15 Rd1! is very hard to meet. Once the rook got to d4, Black still seemed safe enough until White uncorked the remarkable 17 b4!! (probably 16…Qb6 was better than 16…Bc5, but that was almost impossible to see). Although Black had many options, the foundations soon crumbled and Onischuk won this game.