Where did I go wrong?

Hello there,

In the attached URL I was playing as black and felt that my opening and early middle game was solid, but then somehow ended up in a losing in the endgame. Would you be able to give me any pointers on how I could’ve played better?

Thanks,
James:

26...Nb4? looks like the decisive error: loses a pawn.
26...Ra8 was equal.
You also played too fast. You lost this 10+0 game with 2 useless minutes on your clock.

@tpr, is this good? (And that while i had some classical games where i was playing like it was bullet, sometimes ending with more time then when i started...)

"i had some classical games where i was playing like it was bullet, sometimes ending with more time then when i started"

• That cannot be right.
  I wrote my opinion in a blog:
  https://lichess.org/@/tpr/blog/time-is-a-resource-use-it/sPHvUHJz

[@]tpr, I agree, it was in ''the beginning'' when i just switched from blitz to classical (still thx for the tips!). Lately i play more games as i'm supposed to, using as much as my time as possible.

@TheRealYeti2525 said ^

Hello there,

In the attached URL I was playing as black and felt that my opening and early middle game was solid, but then somehow ended up in a losing in the endgame. Would you be able to give me any pointers on how I could’ve played better?

tpr said that 26 ... Nb4 was the critical mistake, but personally I really don't think so. I think the critical mistake was 24 ... Rd8+. That move stops you from being able to play Re5 to defend the pawn on a5.

Outside of the critical mistake though, there are some interesting things about the game that allowed your opponent to force lines upon you. Isolating a pawn early in front of your king can be extremely dangerous, and that pawn being targeted forced you to make moves that you may not have wanted to make otherwise. Be wary when isolating pawns.

Also, what was the idea of a5? It weakens your pawn structure on that side and I don't really see the goal of the move.

P.S. I haven't checked the engine, so maybe I'm wrong on some of my analysis.

"the critical mistake was 24 ... Rd8+"

• It is not the most active, but no harm done.

"Be wary when isolating pawns."
'He who fears an isolated Queen's Pawn should give up Chess.' - Tarrasch

Thank you for your replies.

I originally played a5 because I was thinking about trying to keep my c5 knight on an active square and was trying to shut down any a3...b4 ideas, but I suppose I should’ve only played that if a3 or c3 was played. It also turned out in the game that the knight was traded anyway so I gave myself that weakness for nothing.

Both that idea and the Re5 move were ideas that I didn’t consider during the time so thank you. I thought my knight would just exchange the pawns and all would be even but it didn’t turn out that way. I now think that my pawns being on light squares made it especially dangerous to allow the rook in by taking my pawns.

It really helps to hear other perspectives as engines don’t tell you the ideas behind why a move isn’t ideal, so thanks again.

@tpr said ^

"the critical mistake was 24 ... Rd8+"

• It is not the most active, but no harm done.

24 ... Rd8+ dooms your pawn or forces your rook to a8, where it will be totally inactive.

"Be wary when isolating pawns."
'He who fears an isolated Queen's Pawn should give up Chess.' - Tarrasch

The relatively known theory of an IQP is different from isolating a random pawn in a 960 game.