Cheese - A fast ball. Bill Lee (The Wrong Stuff, 1984) translates Dennis Eckersley's "cheese for your kitchen" as meaning "a fast ball up and in" and added that Eckersley also called himself a "Cheese Master."
Hard cheese - a fast ball. "[Nolan Ryan] threw some good hard cheese up there" (Wally Backman, quoted in St. Petersburg Times, Mar. 5, 1987)
Etymology. Even though the term is relatively new to baseball, it may have a much older basis. London Guide (1818) defined "cheese" as standing for "the best thing of its kind."