1. c2c4 Just like So did yesterday, Aronian decided to use the English  Opening in the must-win game. 1... c7c5 The symmetrical move is  considered the most solid answer against the English. 2. b1c3  2... g8f6  3. g2g3  3... d7d5  4. c4d5  4... f6d5 Now it is a reversed Accelerated Dragon. 5. f1g2  5... d5c7  6. d2d3  6... e7e5  7. c1e3  7... f8e7  8. a1c1 The extra tempo promises White some extra  possibilities. He can, for instance, attack the pawn on c5 before  castling.