mistakes vs. blunders


In the analysis, it's simply a matter of the change in computer evaluation with a blunder defined as a move which leads to a 2 point or more worsening of the evaluation.
Other terms like inaccuracy and mistake bring about lesser declines. I don't remember the exact cutoff for those.
There is some adjustment of the definition once the game evaluation swings decisively.
In computer analysis a blunder is a large decrease in the evaluation. For example if you are ahead 6 pts and then lose your knight, the evaluation will reduce to ahead 3pts and it is a blunder. You may still be winning or have a winning position. It doesn't necessarily mean a mistake that will lose you the game. To mess up a large advantage is still a blunder even if you eventually win the game.

It's the relative cost of the error. A mistake is a smaller error. A blunder often loses the whole game or advantage. A mistake could simply mean you played a sub-optimal move. Even more subtle is an inaccuracy where you aren't getting the most out of a situation.

Blunder= You're basically gone
Mistake= You're kinda gone but not as gone as a blunder
Not necessarily. Lets say you have 2 moves to play.
One move is a mate in one.
One move captures the opponents queen.
If you miss the mate in one, and capture the opponents queen. A chess engine will label that move a blunder. So all this blunder, mistake and stuff can be misleading at times.