[iopq]

That's not applicable to chess. Some blunders are deep and neither player sees mate in 10.

The computer immediately sees mate in 10 and calls the last move a blunder. The opponent misses the mate in 10 and moves elsewhere, the computer puts it as a blunder.

Both players blundered without even seeing a clear win, and it would take them an hour of analysis to see the exact sequence and prove there's no way to escape it even though there are a hundred variations