
Checkmate.
The Big Bang Theory Season 11, Episode 15

Oh, is it? We're conversing.
Checkmate.
The Big Bang Theory Season 3, Episode 11

Checkmate.
The Big Bang Theory Season 12, Episode 17

Checkmate on Sheldon.
The Big Bang Theory Season 4, Episode 22

...isn't that CHECKMATE
and I win?
The Big Bang Theory Season 5, Episode 18