This one is told about Walter Johnson, and about Nolan Ryan, and probably about other notable fireballers.
Johnson (or Ryan) fires a fastball, and the batter swings and misses. He hurls another, and the batter takes another futile hack, then carts his bat back toward the dugout.
"Hey," the umpire calls. "You still have a strike left."
"I know," replies the defeated batsman. "You can have it. It won't do me any good."