Noun
(one's) strong suit (plural strong suits)
(informal) A field in which, or task at which, one is quite capable.
That area isn't my strong suit, but I can give it a shot.
Idling is not my strong suit. Cam Gigandet
Propriety's never been Adrian's strong suit. Richelle Mead
Mothers are supposed to listen and, afterward, to respond with some wisdom and perspective, but these things were not my mother's strong suit. Anne Lamott
I was dyslexic, so math and formulas were not necessarily my strong suit. James Van Der Beek
He cut the connection before she could answer. Long goodbyes weren't anyone's strong suit. Daniel Abraham
Our strong suit is what we do, and our audience. Jerry Garcia