Why did I get a miss here?

https://www.chess.com/analysis/game/live/62907020901?tab=review

on move 45 it gives black a miss but I only chose a mate in 9 instead of a mate in two. Shouldn't a miss only be if you now don't have the sequence?

thanks, 

g6

Seems like missing a mate in 2 would qualify, even with another mate being forced. 

I guess chess.com counted it as a miss because 7 moves can make all the difference when you are low on time or when there hasn't been any pawn advances or captures for very long (50 move rule)

It doesn’t (or at least isn’t meant to, I think…? Idk) account for time.

When wouldn't a missed Mate in 2 not be a miss?

When a forced mate is still found

at least this was the case before the new term miss… now that term is there, maybe things are different

You still missed the Mate in 2, so the evaluation of that move is a miss. There is no look ahead to see what ensues. After move 45 you missed a mate in 2.  The code is simple to write: Was there a better move? Yes, look a mate in 2 was missed. Ta Dah!  A missed opportunity.

My point is that the logic to determine the move classification is  a simple straight forward "what was missed?", not the "ya but the game eventually ..."  type evaluation.

There used to be a look ahead type thing, and I think in the opinion of the OP (and in my opinion) it was better that way. If you play a M3 instead of an M2 that shouldn't drop your accuracy, as it is still a quick forced mate.

M2 - Rc2 would have been best. Checkmate was fastest (forced Ka1, Rc1#) if you had done this.