Anne Curzan at Lingua Franca has an interesting investigation of the phrase “in [my, etc.] wheelhouse”:
The Oxford English Dictionary dates the word wheelhouse, referring to the pilothouse on a boat that contains the wheel, back to 1835. And for over 100 years, from what I have found, all written references to people “in the wheelhouse” describe the person’s physical location in the wheelhouse of a boat. The OED does not yet have a definition for the metaphorical extension of the word, from the place on the boat where one is in control to other sweet spots (assuming this is the metaphorical extension).
Baseball holds the key to the transition from boats to areas of personal strength.[…]
The earliest baseball reference she found was from 1964; in an Update she credits Ben Zimmer with finding examples back to 1959 in Paul Dickson’s The Dickson Baseball Dictionary. I’ve always liked the phrase, which I learned as a young baseball fan, and always wondered how it got to mean “in the area where a hitter likes to hit a ball.”