Adrian Beltre's first game in the majors came on June 24, 1998, at Dodger Stadium. He wasn't even three months past his 19th birthday when the Dodgers called him up from Double-A to bat eighth in a game against the Angels. In his first plate appearance, against Chuck Finley, he lined an RBI hit to left field, whipping the bat through the strike zone with the same controlled violence he still possesses 19 years later:
That's a pretty amazing video. First of all, Beltre hasn't aged a day. He looked 38 when he was 19.