Griffey took the first pitch low, then he got one in his wheelhouse and blasted it.
2004 May 21,Adam Sternbergh,“Boy, Interrupted”, inNew York Magazine:
His new role, as Peter Pan author JM Barrie in Finding Neverland, is right in his wheelhouse: No other actor seems better equipped to play a man fixated on, and trapped by, perennial youth.
2008, John L. Hilley, The Challenge of Legislation: Bipartisanship in a Partisan World:
But the subject matter was right in his wheelhouse — politics and all the moving parts.
Wikipedia states "Wheelhouses are the small enclosed parts of a bridge which historically held the ship's steering wheel." So "in someone's wheelhouse" refers to something being within one's areas of competency, like command of a ship is within a ship captain's abilities.