1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g8f6  5. e1g1  5... f6e4  6. d2d4  6... b7b5  7. a4b3  7... d7d5  8. d4e5  8... c8e6  9. c2c3  9... f8c5 Nothing up to here can be considered a huge surprise. Hikaru has only been playing e4 with White, and Caruana repeated the same Bc5 Open Spanish that he recently chose against MVL. 10. b1d2  10... e8g8  11. b3c2  11... e4f2  12. f1f2  12... c5f2  13. g1f2  13... f7f6  14. d2f1  14... f6e5  15. f2g1 All of this is well known theory, but I think Caruana fell into the same practical trap that Firouzja did against Nepo. I'm quite confident Black's position is objectively fine here, but in practice, it feels so much easier to play the White side. 15... d8d6  16. c1e3  16... e6f5  17. c2b3  17... a8d8  18. d1e1  18... c6a5  19. e1f2  19... a5b7 Both sides were still playing very fast. 20. a1e1  20... c7c5  21. f1g3  21... f5d3  22. f2d2  22... c5c4 In my opinion, this is the move that lost Caruana the game. The position is incredibly hard to understand, but I think the main point is that Black will not be able to maintain his pawn on e5. It will inevitably have to move to e4. When this happens, Black will really regret having pushed c5-c4 because he loses any hope of fighting for the dark squares, plus the light squared bishop can end up stuck on d3 and unable to fight on other relevant parts of the board. White is only a bit better still, but Black's position feels nearly impossible to play. 23. b3d1 White does not exchange the bishops. He has already seen that d3 will become a piece of dead wood. 23... d8d7  24. e3f2  24... d7f7  25. g3h1 An excellent decision from Hikaru. The move is not at all subtle, White wants to take on e5, or to play Bg3 next. Black clearly will have to move the e-pawn. 25... e5e4  26. f3d4 This is exactly the kind of position that I think is a practical nightmare for Black. Long term, he will face huge issues as his pawns are blockaded in the center, and White will eventually take them by having a larger total number of pieces on the board. Black's compensation is that one of his pieces is bigger than White's, but the main power of a larger piece over a smaller piece, such as a rook over a bishop, is being able to attack multiple targets at once. And what do we have here $2 Black's rooks are both clearly on their best squares already. In fact, all of his pieces look nice and active. But what is there to target $2 White has no weaknesses. Slowly but surely, he will activate his pieces and organize them to attack the pawns. Caruana surely could have defended better from here, but in human terms, I think the game is already more or less lost, even though the machine gives White only a 0.5 advantage or so. I think his big mistake was c4. 26... d6g6  27. h2h4  27... b7c5  28. h4h5  28... g6d6  29. d1g4 White's pieces are springing to life, and he is now winning. The bishop on d3 might look nice and anchored, but it is not doing much, and it is unable to help Black fight for squares like f5 or e6. 29... h7h6  30. d2e3  30... d6f4  31. e3f4  31... f7f4  32. d4e6 In my opinion, Caruana only made two serious mistakes all game. One was to play c4. But, the second one was to not resign here. At this point, I really cannot imagine Hikaru ever not converting this with White. Under other circumstances, I would not criticize continuing the game; Black is not totally out of practical hope. But in this particular case, Caruana has a huge game with White against Nepo tomorrow, now a full point ahead of him. It's about as clear of a must-win scenario as one could imagine, and it is clearly the most important game of the tournament. Caruana will have White, and he should definitely get his chances. But having a couple extra hours to rest and prepare for the Petroff would have been a huge asset, and in my opinion, a much larger one than hoping for the 1\% chance of Hikaru not winning this position. 32... c5e6  33. g4e6  33... g8h7  34. e6d5  34... f8f5  35. d5c6  35... f5h5  36. f2d4  36... h5f5  37. h1f2  37... f5f7  38. b2b4  38... h6h5  39. a2a4  39... b5a4  40. c6a4  40... h5h4  41. d4e3  41... f4f5  42. e1a1 Hikaru made his life a little tougher here and had to find some only moves, but they were pretty straightforward. He did not take long to find all of them. 42... h4h3  43. a1a2 Luckily for White, there wasn't much choice. This was the only way to prevent h2+. 43... h3g2  44. a4d1 Another good move, stopping Rf3. 44... f7f6 Now, last up is not letting Black defend the pawn with Rg6. 45. d1g4  45... f5d5  46. g1g2  46... f6g6  47. g2g3 White has reached an ideal coordination again with no counterplay, and now the game wins itself. 47... d3f1 Finally that bishop gets to move... but it still isn't doing anything on f1 and has to come back to d3 the next move anyway. 48. e3d4  48... f1d3  49. g3f4  49... h7g8  50. g4f5  50... g6h6  51. f2g4  51... h6d6  52. g4e3  52... d5b5  53. d4c5  53... d6f6  54. f4e5  54... g8f7  55. e3d5 I'm not sure it was necessary to let Black get the pawn to e2, but Hikaru kept it all under control. 55... f6f5  56. e5f5  56... e4e3  57. f5e5  57... e3e2  58. c5f2  58... b5b8  59. f2e1  59... b8e8  60. e5f4  60... g7g5 Now again, White needed a couple only moves... but they are not hard. 61. f4g3  61... e8e6  62. g3f2  62... e6h6  63. f2e3  63... h6e6  64. e3f2  64... e6h6  65. d5e3 Of course, White does not repeat a second time. 65... h6f6  66. f2g3 