How to realize this +2 evaluation in the Ruy Lopez, Steinitz defense I played a game as White using the Ruy Lopez: Steinitz defense against a lower-rated player (1594 vs. 1500 on chess.com). While I won the game due to a blunder by my opponent in a drawn endgame, the engine gives an almost +2 evaluation in the opening (+1.7 by move 10). But my advantage slowly decreased until it was a dead drawn 0.0 by around move 15. This was a 10 minute game, in case that is relevant.
[Event &quot;Live Chess&quot;]
[Site &quot;Chess.com&quot;]
[FEN &quot;&quot;]
[Date &quot;2021.05.21&quot;]
[Round &quot;?&quot;]
[White &quot;Me&quot;]
[Black &quot;NN&quot;]
[Result &quot;1-0&quot;]
[ECO &quot;C62&quot;]
[WhiteElo &quot;1594&quot;]
[BlackElo &quot;1500&quot;]
[TimeControl &quot;600&quot;]
[EndTime &quot;22:27:44 PDT&quot;]
[Termination &quot;White won by resignation&quot;]

1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4 exd4 5. Nxd4 Bd7 6. O-O Be7 7. Re1 Nxd4 8.Bxd7+ Qxd7 9. Qxd4 Nf6 10. c4 c5 11. Qd3 O-O 12. Bg5 Rad8 13. Bxf6 Bxf6 14. Nc3 Bxc3 15. Qxc3 b5 16. Re3 Rfe8 17. Rg3 g6 18. f3 bxc4 19. Qxc4 d5 20. Qxc5 dxe4 21. fxe4 Rxe4 22. Re3 Qd4 23. Qxd4 Rdxd4 24. Rxe4 Rxe4 25. Kf1 a5 26. Rc1 Re5 27. Rc7 Kg7 28. Kf2 h5 29. Ra7 Kf6 30. Ra6 Kf5 31. Ra7 f6 32. Rh7 Re4 33. Ra7 a4 34. Ra5+ Ke6 35. b3 axb3 36. axb3 Rb4 37. Ra3 Kd5 38. Ra5+ Kc6 39. Ra6+ Rb6 40. Rxb6+ Kxb6 41. Ke3 Kb5 42. Kd4 Kb4 43. Kd5 Kxb3 44. Ke6 g5 45. Kxf6 g4 46. Kg5 h4 47. Kxh4 g3 48. Kxg3 Kc4 49. Kf4 Kd5 50. Kf5 Kd6 51. Kf6 Kd7 52. g4 Ke8 53. Kg7 1-0

My justification behind trading the dark-squared bishop was to have the d5 square for my knight. However, it pretty clearly backfired quickly as my opponent just made the same trade as soon as it was possible. Then we were back to a fairly symmetrical position. I'm assuming the evaluation came from the d5 square for my knight, but otherwise, I don't see how to make use of this advantage. By playing out some alternative moves with the engine, my opponent's dark-squared bishop makes it to d4 and they get their own great piece.
What was the correct plan here for White to keep this advantage?
First things first, I don't believe thinking in terms of computer evaluation is useful at all for humans. We don't look at a position and go &quot;Well, I guess that's about a +0.54&quot;.
Instead, I'd focus on the key elements of the position. By move 15, Black has a weak pawn on d6 that will probably stay weak for the entire game, while the d5 square is a great outpost for the White pieces. This reasonning leads us to what went wrong. Instead of keeping control of the semi-open file and weak square, you went on an attack on g7. That's okay, but you should have consolidated your position first. Moves like Rad1 and b3 would have been useful.
By move 21 your position has transformed. You're a pawn up but your pieces are poorly coordinated and Black controls the newly open files. Most endgames you will get into will be drawn with correct play and if anyone has a chance to create an attack, it's definitely Black.