White gets mated in 20 moves making 1 mistake and 0 blunders

http://en.lichess.org/kZzxpBUU#0

the nimzo is just too good

huge blund of stockfish:)

hehe it really confused the comp for awhile, thinks its equal equal equal and then suddenly its mate in 7

I first time see situation like this, maybe server had error.Engine Stockfish, which analyse game is completely crushing, and always see mate in "only" 7

Horizon effect.

#1 Bwahahaha... I'm guessing that chess isn't solved yet. I imported the game into my computer and got a similar result (white average cp loss: 4).

It happens to the best of us, including Stockfish :D

Wow. So wouldn't 16. Nxe6 be considered a blunder?

Note that the server analyzes thausands of games so every individual game gets almost 0 analyzing time. So it's no wonder that the analysis is not THAT accurate.
BTW what you mentioned is a bug which should be told to thibault. The engine seems to not take overlooking a mate as blunder.

It's not just one mistake. 9. a3 and 10. h3 is slow and optimistic at best and this approach is probably flat out wrong. 9. f3 makes more sense.
By the way the game is well-known, Van Wely - Acs 2002.