strong suit

noun
1.
Bridge. a long suit that contains high cards.
2.
Also called strong point. one's most highly developed characteristic, talent, or skill; forte:
Patience is not his strong suit.
Origin
1860-65
British Dictionary definitions for strong point

strong point

noun
1.
something at which one excels; forte: tactfulness was never his strong point
Idioms and Phrases with strong point

strong point

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.

strong suit