Origin of strong suit
British Dictionary definitions for strong point
Idioms and Phrases with strong point (1 of 2)
Also, strong suit. An area in which someone or something excels, as in That beautiful lobby is the building's strong point, or Writing is her strong suit. The first term was first recorded in 1840; the variant alludes to various card games, in which it signifies the suit with the highest or most cards.
Idioms and Phrases with strong point (2 of 2)
see strong point.