Chess Opening Theory/1. e4/1...c5/2. Nf3/2...d6/3. d4/3...cxd4/4. Nxd4/4...Nf6/5. Nc3/5...a6/6. Bg5/6...e6/7. f4/7...Qb6/8. Qd2/8...Qxb2/9. Rb1/9...Qa3

= Sicilian Defence, Poisoned Pawn Variation = This is the only move for Black's queen, and so should be self explanatory. Another move, 9...Nxe4? drops a piece not to 10.Nxe4?? Qxb1+ and Black is winning, but 10.Rxb2 Nxd2 11.Kxd2 and White is winning.

Here White has a few choices. The most popular is 10.f5, applying direct pressure to e6. Then Black usually plays 10...Nc6 11.fxe6 fxe6 12.Nxc6 bxc6 13.e5 dxe5 14.Bxf6 gxf6 15.Ne4, when Black's best is 15...Qxa2 (or 15...Be7 16.Be2 h5 17.Rf1!, with a strong attack).

White's other choices are 10.e5 and 10.Bxf6.

Theory table
.

'''1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5. Nc3 a6 6.Bg5 e6 7.f4 Qb6 8.Qd2 Qxb2 9.Rb1 Qa3'''