1. d2d4  1... g8f6  2. c2c4  2... g7g6  3. b1c3  3... d7d5  4. g1f3  4... f8g7  5. c4d5  5... f6d5  6. e2e4  6... d5c3  7. b2c3  7... c7c5  8. a1b1 In the 1990s this pawn sacrifice went under thorough check, long  before the computers became as strong as they are nowadays. There was  never a definite verdict of what the evaluation should be, but both  Grunfeld experts Vachier-Lagrave and Nepomniachtchi dare to play it  regularly. 8... e8g8  9. f1e2  9... c5d4  10. c3d4 