28 b2xa3 Black gains the isolated White a3-pawn as a target Carlsen vs Aronian, 2007  (C78) Ruy Lopez, 36 moves, 0-1 23 Qc2-c3 forces 23 ... f7-f6 and futher weakening of g6-square Gelfand vs Eljanov, 2008  (A17) English, 38 moves, 1-0 20 - Be7-g5! forces 21 e2-e3 and further weakening of f3-square Kramnik vs Carlsen, 2008  (A30) English, Symmetrical, 57 moves, 0-1 8 ... f7-f5, 12 ... d7-d6 weaken e6-square for 23 Nf4-e6 Kamsky vs E Alekseev, 2007  (E17) Queen's Indian, 37 moves, 1-0 17 .. e7-e5! leaves White with isolated e4-,c5-pawns weaknesses Kramnik vs Shirov, 1996  (D15) Queen's Gambit Declined Slav, 35 moves, 0-1 49 .. Rb6-b2! Black focuses *all* of his pieces on weak a2-pawn Leko vs Kamsky, 2008  (C95) Ruy Lopez, Closed, Breyer, 61 moves, 0-1 6 games