What are the definitions of Blunder,Mistake and Inaccuracy in Computer Analysis?

?!?

I ask because sometimes the computer considers a move that causes mate vs you as a mere mistake and instead failing to take a pawn as a three questions marks blunder .

How does the computer consider simplification sacs when you're ahead of material and you give back some of the material just to cut all your opponent counterplay and secure the victory?

best i know is that the definitions depend on the magical math that the computer uses to analyze.  just to make up numbers, less than 1 point would be an innaccuracy, 1 - 2 points would be mistake, etc. 

as for the mate deal, maybe it is just pity since you feel bad enough for blundering into mate anyway. 

i will be even less helpful if i try to answer anything else, so i will quit with that. 

has anyone gotten an exclamation point from the thing

yes, but i have also gotten inaccuracies that lead to mate in 1.  so...shrug. 

once in a computer workout (or one of the tools) i played a drawn position for so long the computer said "amazing, you found a way to win when you shouldn't have".  i half expected it to start a "why wont my opponent resign" thread. 

can you show the game with the exclamation point, and what the computer said

it appears that all of my analyses have been deleted from chess.com.  i never bothered to save them in a pgn, so i guess i can't.  if i find something i think i can reanalyze with an ! i will let you know.  but, it is really fairly rare, so i am not optimistic. 

I always assumed blunder meant a move that flat out loses, ie leads to mate, a lost ending, leaving a piece hanging etc. and that a mistake was a bad move, but not as bad as a blunder.

I've also noticed the anonymous analysis program here occasionally marks perfectly valid opening moves with a ?, I guess because such moves don't fit in with it's style or paramaters. Whatever, dude.

Overall it's certainly way better than nothing & very fast, it's usually good enuff to show me where I screwed up after losing a game and if not I always have Fritz 12 available. Some of it what it has to say ("book move" after every book move) is a waste of (my) time, but maybe useful to other players.

I don't know why any info on what program is being used or any other details such as the PC it's running on, CPU, RAM etc is such a big secret, but it is. Maybe the PC is moonlighting here and it was really built for the CIA, NSA or NASA?

I think:

Inaccuricies: Minor problem maybe positional wrong capture etc.

Mistake: Loses 1-2 points or gets in a very bad position

Blunder: Loses a piece or THE GAME

http://support.chess.com/Knowledgebase/Article/View/153/0/in-the-computer-analysis-whats-the-difference-between-inaccuracy-mistake-and-blunder

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oh, good thinking.  never occurred to me that it may be listed on the sight somewhere.  but hey, i was right(ish). 

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 Thanks. By intuition it should be like this: all moves that lead to the loss of your king are blunders, and all blunders and mistakes that you make when you're winning  should be considered as inaccuracies instead if after that move you still hold the advantage

.3 inac

.9+ mistake 

 

2pts+ blun

I think this is about the best answer there is. Defintly a clear answer...

https://support.chess.com/customer/portal/articles/1444907-in-the-computer-analysis-what-s-the-difference-between-inaccuracy-mistake-and-blunder-

Link goes to a page not found error.  Does anyone know of an updated link?

It really depends, but I call a move blunder, if there is a single forced line after that move leads to a huge loss. For example you may blunder your queen by either putting it directly in front of opponent piece to capture, or indirectly by e.g. letting your opponent fork your queen by night (so two move capture), this scenario can go longer but it doesn’t have any branch, in other words by looking at direct threats you can easily calculate it without a mental effort.


I call something mistake, when you can feel a danger of losing material but you may have to calculate two or three branches to see it. I call it inaccuracies when it doesn’t lead to direct material loss but rather positional disadvantage. The latter is quite hard to see even sometimes after the games (at the time of playing it is almost impossible).

Anyone else can have a different definition.