[casion]

That's not correct if utilizing terms that are common chess parlance.

"Mate in..." implies that a mate will occur, with a forcing sequence, with the longest branch being the announced number of moves.

Given that chess is not solved, nobody can claim "Mate in..." from the starting position.

[bluGill]

I doubt any grandmaster will have any problem in forcing mate in less than 40 against me. Many real games don't get beyond 40 against opponents who are not nearly at that level.

[apetresc]

You are still ignoring what multiple people have tried to explain to you.

"Mate in X" is not a show of bravado about how quickly a grandmaster things he can beat _you_ specifically. It's a mathematical property about a position. It doesn't matter if Carlsen or a chimp are sitting on the opposite side of the board, "Mate in X" means the same thing.

[bluGill]

I'm intentionally ignoring it.

[mlyle]

Well, that's helpful and a good use of everyone's time.

We have the lingo because while chess is not solved, "mate in ___" are situations where there is a definitive, provably optimal solution all the way through the end of the game. Calling "mate in 40" at the beginning is not one of them, no matter the relative strengths of the players involved.