The games in question proceeded as follows: 10.fxg5 Nfd7 (Black aims to route a knight to e5, and then back it up by a knight at d7 or c6) 11.Nxe6 (Efim Geller's discovery) 11...fxe6 12.Qh5+ Kf8 13.Bb5. Here Panno played 13...Ne5, while Pilnik and Najdorf chose 13...Kg7; however, all three Argentine players lost in very short order and the line was, for a while, considered refuted. In 1958 Bobby Fischer played 13...Rh7!, versus Svetozar Gligorić at the Portorož Interzonal, in a critical last-round game. According to modern opening theory, this position is a draw at best for White. A 10,000 node analysis by Leela Lc0 departs from this line with 11. Bg3. Black can route the knight as intended 11...Ne5. White blockades the h-pawn 12.Qh5. Black can take the g5-pawn, leading to a knights exchange 12...Bxg5 13.Nf3 Nxf3 14.Qxf3 7...Qb6 one of the most popular choices at master level. 8.Qd2 the extremely complicated Poisoned Pawn Variation: 8...Qxb2 9.Rb1 (9.Nb3 is the other less common option) 9...Qa3 and here White has played both 10.f5 and 10.e5. Both lead to extremely sharp play where the slightest inaccuracy is fatal for either side. Since 2006, when it was played in several high-level games, 10.e5 has become very popular. From the standpoint of the theory, it is regarded as White's only attempt to play for a win against the Poisoned Pawn Variation since all other variations (and that includes the other pawn move, 10.f5) have been analyzed to a draw with the best play. An example is a game Vallejo Pons–Kasparov, Moscow 2004, which was called "a model modern grandmaster draw!" by Kasparov himself in Revolution in the 70s (page 164). 8.Nb3 White opts for a quiet game, but Black has nothing to worry about: 8...Be7 9.Qf3 Nbd7 10.0-0-0 Qc7 where we have reached a setup very similar to that of the old main line mentioned above. However, without the d4-knight White will find it very hard to organize an attack. 8.a3 is a more challenging reply for White. It protects the pawn indirectly as 8...Qxb2 is met by 9.Na4! winning the queen. Black usually plays 8...Nc6, although 8...Nbd7 is also playable. The 8.a3 line has been seen several times at the grandmaster level recently. 7...b5 the ultra-sharp Polugaevsky Variation. Black ignores White's threat and expands on the queenside. 8.e5 dxe5 9.fxe5 Qc7 here White either plays 10.exf6 Qe5+ 11.Be2 Qxg5 or 10.Qe2 Nfd7