Mate in 2 or 5


Missed a mate in 2 but saw a mate in 5 - both ultimately checkmate, however the computer analysis deems this a mistake. Does anyone like me think that's illogical in principal. I understand that chess is fundamentally all about being efficient, therefore I would consider that to be an innacuracy. I am probably missing the point so please don't lambast me for this thought.

That sometimes happens to me
In the computer analysis,
what's the difference between
inaccuracy, mistake, and blunder?

When you are reviewing the output from a Computer Analysis of a game,

it can be useful to know how terms like "inaccuracy," "mistake," and "blunder"

compare to each other.

Assuming the position is roughly even (no big advantage for either white or black),

it works like this:

"Inaccuracy" - The computer evaluates that this move resulted in a position

that is at least 0.3 points worse than the position resulting from the best move


"Mistake" - This move is at least 0.9 points worse than the best move available

"Blunder" - This move is at least 2 points worse than the best move available -

pretty bad!  :)

These values are somewhat relative to existing/previous advantages held by

one player or another.  For instance, if you are already massively ahead - say,

by 30 points - and you make a move that drops your evaluation to +28,

you're still massively ahead; relatively speaking, the size of your advantage

hasn't changed significantly. 

Therefore, such a move would not be labeled a blunder.