[%c_effect a4;square;a4;type;GreatFind;persistent;true]
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g8f6  5. e1g1  5... f8e7  6. d2d3  6... b7b5  7. a4b3  7... d7d6  8. c1d2 A curious move, considering we learn early on that it's better to develop knights before bishops in the opening. White has several more natural moves, but the bishop on d2 has its uses and the Ruy Lopez is such a well-researched opening that you have to break the most conventional rules to try to outwit your opponent. 8... e8g8  9. h2h3  9... h7h6  10. f1e1  10... a8b8  11. a2a3  11... f8e8  12. b1c3  12... e7f8 The last moves by both sides were all very reasonable. 13. c3d5  13... f6d5  14. b3d5  14... c6e7  15. d5b3 [%c_effect b3;square;b3;type;GreatFind;persistent;true] The right square, as now White has the plan of playing a3-a4 and using the a-file. 15... c7c5 A new move that was probably prepared beforehand, as Keymer played it quickly. It was predictable that this position could happen, since Praggnanandhaa played all of this in a 2023 game.