The variation suggested for move 13 (...Bg4) says I have a decisive advantage by move 22 (...Nxg4) when I'm about to be checkmated.

 Has the computer analysis gone crazy?

The computers can only 'count' how a position looks by itself, without respect to the future moves. In this position you have material advantage so it thinks you have good advantage.

The analysis that the computer does is done by attaching to its evaluation of the current position evaluations of possible future positions. By the evaluation of the future positions it judges value of the current position. The problem is that the evaluation can only go as far as you allow it. In this case the computer calculated 8 moves ahead and saw you have material advantage, so it thinks you should have played that. If you have given it some more time to think it would have seen that you'll get checkmated in the next move and it would have changed it's suggestion :).

That is you didn't find a computer analysis bug, rather chess.com saving cpu cycles .

However it is possible that the suggestion is still right, just not the whole suggested variation.

Yes, this seems like an isolated horizon error in the computer analysis. Sorry for the mistake!

*trying to hold back laughter* : But... you're up two pawns :P

Also, @kounenis : The move may have been better than what he played, but you have to question it because the computer clearly failed to analyze the line properly.

Presumably that's a matter of computing resource availability, not functionality -- they are somewhat different issues.

I know what you mean, I just got my analysis back, and I was playing Black. It said I had like 8 blunders, 11 mistakes and 5 inaccuracies or something ridiculous. This was against a 1800 or something. I admit I made a few blunders and mistakes, but not like this.

The analysis of my 'blunders' made no sense, in some parts of the game I went from, say, +1.21 to +1.10, and it calls this a 'blunder' (I was playing as White). The alternative moves were also pointless.

Also, at one point, it said I made a 'blunder', showed me an alternate move which lead to my opponent, playing as Black, to checkmate me 3 moves later. The computer called this position, in a checkmate by my opponent, a 'decisive advantage' to myself.

FAIL! -.-

All of my computer analyses at the moment come back awfully. I've got things saying that my advantage is +94.68 and its variations make no sense at all.

Yeah, its really weird at the moment.. perhaps there is something faulty with the system because this has only happened to me recently..

yeah i believe my last analysis was weird too.... it told me that when i played a move that led to a mate in 3 that it was a blunder.... it suggested a line which didnt even lead to checkmate