Black has to capture the pawn, otherwise the rook goes to a6.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8  5. c1d2  5... c7c5  6. a2a3  6... b4c3  7. d2c3  7... f6e4 [%c_effect e4;square;e4;type;GreatFind;persistent;true] It's necessary to capture White's bishop while there's still time, otherwise the pair of bishops guarantees a lasting positional advantage. 8. g1e2 Getting ready to capture on c3 with the knight, where it will be well placed. 8... b7b6 There is no rush to capture the bishop since it has nowhere to go. 9. d4d5  9... c8a6 [%c_effect a6;square;a6;type;GreatFind;persistent;true] Developing the bishop while attacking the c4-pawn. 10. b2b3  10... b6b5 [%c_effect b5;square;b5;type;GreatFind;persistent;true] Guaranteeing the activity of the a6-bishop. 11. d1c2  11... e6d5  12. c4d5  12... e4c3  13. c2c3  13... d7d6  14. e2g3  14... b8d7  15. f1e2  15... d7f6  16. c3d2 The opening phase is almost over. Black has achieved equality, but the pawn structure is unbalanced and typical of the Benoni Defense. White has a central majority that could cause problems if it starts to advance, so Black must seek counterplay quickly. The position is balanced, but it's not so easy for Black to play. 16... f8e8 A new move but a very natural one, developing the rook. 17. f2f3 [%c_effect f3;square;f3;type;Interesting;persistent;true] Nakamura immediately prepares to reinforce the center with e4. 17... d8b6 Developing the queen to an active square, although this piece had an important defensive task on f8, protecting the king against a possible knight invasion on f5. 18. e3e4  18... a6c8 The bishop comes back to prevent Nf5. 19. a3a4 [%c_effect a4;square;a4;type;GreatFind;persistent;true] A strong reply, opening the queenside. 19... c8d7 [%c_effect d7;square;d7;type;Mistake;persistent;true] This move is bad because it allows White to divert the bishop from the protection of the f5-square.