context: 1. d2d4  1... d7d5  2. c2c4  2... d5c4  3. g1f3  3... a7a6  4. e2e3  4... b7b5 A much riskier line than the traditional ways of playing the Queen's Gambit Accepted with Nf6-e6-c5. Black's idea is not to end up with an extra pawn, because that is impossible, but to change the pawn structure on the queenside. 5. a2a4 Necessary to recover the pawn. 5... c8b7  6. b2b3  6... g8f6  7. b3c4 The best way to fight for an advantage. It's useful for White to leave the pawns on the a-file. 7... b5b4 Another risky and unusual decision, since White ends up with a formidable pawn center. Here it's perhaps possible to compare the styles of both chess players, with Keymer being a legitimate heir to the European tradition of classical chess (Emanuel Lasker, the second world champion, was also German), featuring positional chess in which moves that break strategic patterns are rarely found. Aravindh, on the other hand, is a representative of the modern chess of India, where chess has become very popular more recently and in which the legacy of ancient positional laws gives way to the computer's cold calculating vision, in which there are no strange moves, only good or bad ones. 8. c4c5 The most direct attempt to refute Black's play. 8... b8c6  9. d1b3  9... e7e5 A new move, certainly prepared at home (or at the hotel room.) 10. f1c4 The critical reaction. 10... d8d7  11. c1b2 White loses any chance of an advantage after this move. 11... e5d4 