I believe that is
flag to crotch four, CHECKMATE.
The Big Bang Theory Season 10, Episode 10
...isn't that CHECKMATE
and I win?
The Big Bang Theory Season 5, Episode 18
to avoid CHECKMATE, and then he did it."
Money Heist Season 1, Episode 7
Checkmate.
The Big Bang Theory Season 11, Episode 15
Checkmate would be irreversible."
Money Heist Season 1, Episode 8