Inability to see
Just finished a game on here which I ended up drawing by repetition because I couldn't see the way to properly solve it. Here's the salient bits:
From 36. Ne6, I couldn't see the way to get positional advantage. The game route ended up being a repeated series of checks to get to a draw by repetition. I did this because I could see the mate in one for white should I let him keep going. However, when I did the computer analysis later, I was shown this line:
In looking at it now, it seems blindingly obvious, but alas, hindsight is 20/20. I will, however, learn from this game not to give up on a position and to try and better explore the options.