In honor of Bryce Harper playing his 162nd career game, here is the list of the Top 12 home run hitters through Age 20 season:1. Mel Ott, 612. Tony Conigliaro, 563. Alex Rodriguez, 414. Ken Griffey, 385. Frank Robinson, 386. Mickey Mantle, 367. Mike Trout, 358. Al Kaline, 329. Bryce Harper, 31(tie) Ted Williams, 3111. Orlando Cepeda, 25(tie) Eddie Mathews, 25Now, some of these players -- Alex Rodriguez, Ted Williams and Cepeda -- actually turned 21at some point DURING the season, something Bryce Harper will not do until October.There are a couple of points worth making here. One, Harper is on pace to hit 60 home runs this year. And while he probably won’t do that, he has to hit 40 this year (31 more in the last five months) to pass Mel Ott for most home runs through Age 20 season.But here’s an even more significant point, I think. Look at the 12 players. Tony Conigliaro seemed on his way to an extraordinary career until he was hit in the face by a Jack Hamilton pitch. the pitch fractured his cheek, dislocated his jaw and caused serious problems to his eye. His comeback was stirring and magnificent -- he hit 36 homers in 1970 -- but his vision was never the same and he was done at 26 (he did try another comeback at 30, making it back to the Majors). He goes down with Herb Score and a couple of others as the greatest “What might have beens” in baseball history.So take away Conigliaro. And take away Trout and Harper because they are active. That leaves nine players.All nine are either in the Hall of Fame or will be in the Hall of Fame (depending on how the voters treat A-Rod). That’s amazing to me. All nine are all-time players.It just goes to show you that this sort of brilliance as a young hitter is very telling and predictive. It’s interesting. Take a look at the pitchers with the most strikeouts through age 20 (since 1901):1. Bob Feller, 7122. Dwight Gooden, 5443. Bert Blyleven, 3594. Gary Nolan, 3175. Larry Dierker, 2906. Mike McCormick, 287(tie) Pete Schneider, 2878. Chief Bender, 2769. Felix Hernandez, 25310. Smoky Joe Wood, 24411. Rick Ankiel, 23312. Walter Johnson, 231Sort of a mixed bag, isn’t it? Pitcher wins through Age 20 looks more or less the same -- you can add Wally Bunker and Milt Pappas and Ray Sadecki, take out Walter Johnson, Rick Ankiel and King Felix. It still gives you an inconsistent mix. Pitchers get hurt -- Gary Nolan did, Smoky Joe Wood did. Dwight Gooden lost his way. Rick Ankiel, well, this happened. That sort of thing does not seem to happen as often to young hitters. Sure, they will occasionally get hurt. Vada Pinson, Claudell Washington, Cesar Cedeno and a handful of others all ran into various problems along the way. But, generally speaking, brilliant young hitters stay brilliant for an extended period of time. Bryce Harper and Mike Trout are obviously a long, long, long way away from becoming all-time players. But I’d bet on both of them.