I had a vague recollection the other day of a comedy bit but not sure where I saw it.
The bit was basically two people sitting down at a table playing an overly simplified version of Chess or checkers. One person moved the piece and said “check” and the other moved it back and said “checkmate”.
I want to say it was either Mork and Mindy, 3rd Rock from the Sun, or Red Dwarf.
Could well be this. That scene ends with Charlie saying “checkmate”, although I must admit I never noticed exactly what he did.
It’s not a big spoiler if you are paying attention to what’s going on in the episode, but Charlie thinks he is actually getting smarter from the pills and does things he thinks are smart but are not. The chess moves he makes are nonsense. The guy actually calls two checkmate moves in a row, which is obviously not possible if the first one was indeed a checkmate.