double checking
I have been doing some double checking on the notion of triple checking. I found this fascinating article on chess cafe.
“Did anyone ever deliver a triple check during a game of chess? Yes, very
probably, if he was playing in Italy more than 120 years ago. To be honest,
to this day I haven’t been able to find a single specimen of such a check
given in actual play, but this was possible in theory thanks to the suspended
Pawn.”