[%c_effect g4;square;g4;type;GreatFind;persistent;true]
1. e2e4  1... e7e5  2. g1f3  2... g8f6  3. d2d4  3... f6e4  4. d4e5  4... d7d5  5. b1d2  5... e4d2  6. c1d2  6... f8e7  7. f1d3  7... c7c5  8. c2c3  8... b8c6  9. e1g1 The position is still known by theory. Black has good central control and free piece development, but the advanced pawn on e5 gives White some chances on the kingside. 9... c8g4 Usually Black plays 9...0-0 or 9...Bg4. This will be the first time a combination of these two moves is played. 10. f1e1  10... e8g8 This is probably inaccurate due to Erigaisi's following play. 11. h2h3  11... g4h5  12. d3f5 [%c_effect f5;square;f5;type;GreatFind;persistent;true] A very unpleasant move to face. The bishop on f5 prevents the normal development of the queen on d7 and supports an e5-e6 advance. If Black plays with Bg6, then it's possible to capture the bishop, with two possible consequences: 1- Black captures with the f-pawn, leaving White with a superior pawn structure; 2- Black captures with the h-pawn, after which White advances e5-e6 and tries to exploit Black's kingside weaknesses. 12... g8h8 A difficult prophylactic move. The idea is probably to anticipate a possible e5-e6 advance. 13. d1e2  13... d8b6  14. d2f4  14... a8e8  15. a1d1  15... d5d4 Play by both sides is quite logical and the tension grows.