A fastball was a kind of baseball pitch known for its speed.
In 1953, Willie Hawkins hit a fastball into the left field bleachers, a feat he recounted the next day for the patrons of Eva's Kitchen. (DS9: "Far Beyond the Stars")
Bob Gibson was known for throwing fastballs. In 2370, when Jake Sisko told his father he had good news, Ben's second guess was that Jake had finally learned how to hit Bob Gibson's fastball. Jake said his news was better than that, which prompted Ben to ask what it was. (DS9: "The Homecoming")