Missed Win

Looking over some of my played games, analysis sometimes reports I had a "missed win." What criteria does analysis use for reporting a missed win?  Is it a mate in x or just an overwhelming or significant  advantage.

The developers always keep a tight lid on exactly how the calculations are done.  With that being said, I believe that a Missed Win is determined from missing a move that put you in a winning position (maybe +3 or something) without your evaluation going to a losing position.  Contrast that with a Blunder which also may have missed a win but now you could be losing.

Could you post a link to the game and move in question?  If it was a forced checkmate, you almost certainly would have been dinged in some way in the Review.

If you have a potential mate in one which cannot be defended by your opponent in all variations, then it would be checkmate next turn if you see it. The computer will label this as a mate in 1.

If you have a potential mate in one which can be easily parried or defended (like a gang-up of queen on g4 and rook on g1 against a pawn on g7 and king on h8 and then the pawn on g7 is simply pushed forward), then it will depend on the context, but there should not be any "missed win" classification by the computer in general.

If you have missed a good opportunity to seize the advantage, then it is a missed win. But if I recall, "missed win" indicates a missed opportunity to obtain an advantage, and for missed mates, the computer likely labels them as "missed mate" instead.

21. Nxf8? bxc3 and the necessary bishop for the checkmate is gone! That is the key point: that bishop on c3 needs to survive for the attack to succeed!

A more forced mate starts with 21. Ne7+, following which Black has to respond to the immediate check, thereby squandering the move needed to capture the c3 bishop and allowing the checkmate to happen.

I see the game.  It is this one: https://www.chess.com/analysis/game/live/37647701557

I think that the a Review algorithm makes sense here with the current definitions.

22. Bxg7 is given an inaccuracy (because it misses the mate in 1 but you still have a forced mate).  It is not a Blunder nor a Missed Win because you still have a forced mate available.

23. Bxf8+ is a mistake because it misses the immediate mate and no longer finds a forced mate.  However, you are still in a completely winning position so a designation of Blunder or Missed Win is not appropriate.

Until we have some new terms or designations, the game review appears to be perfectly logical.

If by this you mean the missed win comes on move 21 (before you made the move 22 blunder), then the computer was right in labelling it as a missed win.

If by this you really meant move 22 itself, follow Alramech's explanation.

I myself saw from the computer that on move 22 itself, a Mate in 1 --> Mate in 9. If I recall, the computer will dispense the text "FASTER MATE" or something like that.

Move 21 is likely a "missed mate" by the analysis.

Move 22 is likely a "faster mate" by the analysis.

I have yet to look at the remaining moves, but there could be some inaccuracies and mistakes dispensed by the analysis even if there is no "missed win".

MISSED WIN?  I HAVE NOT WON IN THE PAST 10 GAMES OR SO.  I SUCK SO BAD AND I'M READY TO LOSE IT.  fING GAME IS NUTS AND SO AM I FOR EVER STARTING THIS .HIT.  GOOD LUCK TO ALL Y0U FERS WHO CAN FIGURE THIS OUT!

Oh, I meant the full analysis rather than the quick analysis on that page.

Not sure if it still exists or not at this point of time.

EDIT: They might have removed it since the introduction of the "Game Review". The last I recalled was that "Missed Mate" exists, but things might have changed.

EDIT 2: I dug up a forum thread for this. It's something like this https://www.chess.com/forum/view/game-analysis/missed-checkmate-2 except that this one is a screenshot from the player on phone (whereas in my case it's a computer browser version)

I have confirmed that in your case on move 22, there was a mate in one but you made a move which was a mate in nine. It is classified as an inaccuracy in that analysis (before the introduction of the Game Review, the analysis would tell me that a faster mate was available - it won't be labelled as an inaccuracy back then - but I have not kept myself updated with the features of the Game Review yet).

Yeah, it's not going to call that a 'missed win,' because it still has you at infinity +1 to win the game. Qa3 would likely do it, though.

I think it is because the clock beat you but you were crushing him if you had not run out of time. Your position on the board was still strongly winning therefore not a missed win.

When I missed a mate in 1 recently the analysis gave it as a blunder. Ironic really. I moved a bishop to skewer K and Q and that was a blunder !