In this game:
lichess.org/SoG5JD0Uaround move 15 I felt I had a clear advantage, but maybe I got too focused on the possibility of winning a piece on c6 (which could not happen) and got involved in a series of bad exchanges and a lost endgame.
Is there anything - apart from just bad calculation - that I'm missing here? Larger strategic ideas? Just analyzing with the engine somehow does not tell much to me. Thanks a lot.
wasn t better 21 Rxd5 ? winning the black queen somehow
I agree 21. Rxd5 is the natural move, but apparently 21. Bxd5+ Kh8 22. e6 is even better for white (not that I saw all of that).
if i m not wrong :
if 21 Rxd5 there s no way to save the queen so can be changed for a rock and a bishop... but white even has Nc7
21 Bxd5 is less powerful move to me. allow easy escape of the king from white bishop threat
Black's strategy had failed up to the point where you gave away your advantage. You played the first 17 moves (and 20. d5) well, even if the computer points out arguably better ways to take advantage. The computer gives ?? to 18. Bd3 and 19. Bc4 since the removal of the pins on c6 gave him the opportunity to disentangle his pieces (not that he did so in the game) while you had alternatives that would have won outright. 18. exf6! Bxf6 19. d5 (or 19. Bxg6) was the time for the break: all of your pieces were placed perfectly for it, and the pawn exchange only helps you by opening up his king.
Note that while the endgame was generally losing, you missed four opportunities:
38. Kd7!
It's not immediately obvious how (or if!) Black can get out of the bind.
49. Bh4!
If he gobbles up your kingside pawns, your bishop will never be able to stop his. Meanwhile, his rook can't stop your passer either, even just against your king, but since it's just one pawn, the most he'll lose is the rook. Note the computer line requires accurate play from Black to draw.
52. Bd8!
Prevents him from sacrificing the rook. From there, you have a trivial repetition draw, or a more complicated line with winning chances.
57. Bxa5!
Again, your bishop cannot stop all of his pawns, so it's time to race for the promotion.
24 Qb3 is a clear win because of the threat Qf7 and mate.