1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. g2g3  4... d5c4  5. f1g2  5... c7c6 Only the sixth most popular move, but even so, it still has more than a thousand games played. The Catalan is a huge opening. 6. f3e5  6... f8b4  7. c1d2  7... b4e7 [%c_effect e7;square;e7;type;GreatFind;persistent;true] 8. e2e3 Protecting the d4-pawn before capturing on c4. 8... e8g8  9. e5c4  9... b7b6  10. e1g1  10... c8b7  11. d1b3 [%c_effect b3;square;b3;type;Mistake;persistent;true] This makes things too easy for Black, since now it's difficult to prevent the liberating c6-c5. 11... d8c8 [%c_effect c8;square;c8;type;GreatFind;persistent;true] Protecting the bishop and preparing c6-c5. 12. e3e4 Trying to create some activity in the center, but this make things worse. 12... c6c5 [%c_effect c5;square;c5;type;GreatFind;persistent;true] 13. d4c5  13... f6e4  14. c5b6  14... e4c5  15. b3e3  15... b7g2  16. g1g2  16... a7b6 A dream position for Black in this queen's pawn structure. She has an extra pawn in the center, good development, pressure on the h1-a8 diagonal and on the queenside. 17. e3f3  17... b8d7  18. d2f4 [%c_effect f4;square;f4;type;Mistake;persistent;true] Too slow. It's necessary to finish the development. 18... b6b5 [%c_effect b5;square;b5;type;GreatFind;persistent;true] 19. c4e5  19... e7f6 [%c_effect f6;square;f6;type;Mistake;persistent;true] Black misses a golden chance to achieve a winning advantage. 20. e5d7  20... c8d7  21. b1c3 White remains a bit worse, but the situation has improved compared to what it was before. 21... c5d3  22. a1d1 It was more accurate to move the rook from f1, since the a-rook has a more important defensive role. 22... d3f4  23. g3f4 A difficult choice. Taking with the queen is also possible, trying to reach and endgame a pawn down, but with flanks only on the kingside. This should be a draw with best play. 23... d7e7 Despite the equal material, White has a long defense ahead of her. She will never be very calm with these weaknesses on the kingside. 24. c3b5  24... a8a2  25. b2b3  25... g7g6  26. b5d6  26... f8b8  27. d1d3  27... f6h4  28. d6c4  28... h7h5  29. c4e5  29... b8b7  30. e5c6  30... e7c5  31. d3c3  31... c5b6  32. c6e5  32... g8g7  33. e5c4  33... b6b4 White always needs to be careful with the multiple weaknesses, but Lee defends well. 34. c3d3  34... b7c7  35. f3e4  35... b4e7  36. e4e5  36... h4f6  37. e5d6  37... c7b7  38. d6c6  38... a2c2  39. f1d1  39... b7c7  40. c6d6  40... e7d6  41. c4d6  41... g7f8  42. d1d2 