The Best and Worst Pitchers To Start in MLB at Age 20 (Since 1961)

In honor of Julio Teheran’s MLB debut on Saturday, I decided to do a little research on other pitchers who have debuted in MLB at age 20 (or younger) in the 50 years of the Expansion Era.

There have been exactly 100 pitchers since 1961 to debut at age 20 or younger (with at least 60% of appearances as a starter); Teheran will make 101, unless he ends up being used as a reliever later in the year. Of the previous 100, 26 have a negative career WAR (Baseball-Reference version). 26 others have a career WAR of 20 or more.

Only 9 of these players are on an MLB roster at the moment: CC Sabathia, Felix Hernandez, Jon Garland, Zack Greinke, Matt Cain, Scott Kazmir, Clayton Kershaw, Edwin Jackson, and Rick Porcello. That’s a pretty great group, even if it does include Jon Garland. All those guys except Kazmir and possibly Porcello look like good bets to end their careers with 20+ WAR. (Kazmir is at 16.9 but looks like he’s done; Porcello’s at 3.4, and it’s too soon to tell).

Here are the top 12 pitchers in career WAR who debuted as a starter at age 20 or younger:

No surprises at the top of the group; Maddux, Blyleven, and Eckersley are all Hall of Famers. Catfish Hunter is also a HOFer, though as his WAR implies he wasn’t the most deserving one. Sabathia looks like a good shot to make the Hall, too; he’s also got a great chance to end up 3rd on this list. Of the other active pitchers, King Felix (25.0 WAR), Greinke (22.6 WAR), and Matt Cain (21.6) will likely move into this group in the next few years. Jon Garland (23.0 WAR) has a shot, too, though he’s older than those other guys and not as good.

What about the worst pitchers? Here are the 12 pitchers from this group with a career WAR below -1:

For obvious reasons, these guys are probably less familiar to you. I remember Hayden Penn pretty well because the Braves demolished him in an interleague game during his age-20 season. He looked like he was pretty clearly not ready to be in the big leagues; I felt really bad for him.

Todd Van Poppel is probably the most famous name, but even he is not famous for what he did on the field. He did have a long career, and even had a couple decent years as a reliever for the Cubs, but his notoriety mainly stems from the 1990 draft. Before the draft, he was considered the consensus top talent, but his salary demands were exorbitant. He ended dropping to the A’s with the 14th pick (remember when the A’s had money?). The Braves had the first pick that year, and they opted for Chipper Jones instead. That’s worked out pretty well.

It’s funny, when I started researching this, I was thinking of some of the worst 20-year-old starters and I came up with names like Oliver Perez, Jeff Juden, and Nick Neugebauer. None of those guys even made this list, though (Juden just missed; he ended with -0.9 WAR). I guess that just goes to prove the fragility of young arms.

One common thread is that many of these players were first-round picks. Schulze, Conroy, Van Poppel, Kipper, and Adamson were all 1st-rounders, and Adamson was the first overall pick. Only two of the players were drafted in any round but the first: Byrd was drafted in the 2nd round and Penn in the 5th. (The rest of the players were not draft eligible: Fajardo is from Mexico and the guys from the early ’60s came along before the draft existed.)

Some pitchers can adapt quickly enough to thrive in the big leagues at age 20, but many cannot. Clearly, being drafted early or being a top prospect is no guarantee of success. These players offer both success stories and cautionary tales in that regard. Many of the recent pitchers to debut at a young age have been successful, though, so it’s possible that teams have learned something about not promoting young pitchers who aren’t ready.

Whether Julio Teheran will be a success or a failure (or somewhere in between) is of course impossible to say. But based on scouting reports about his stuff and his makeup, I’d say the odds are good that he ends up having an impressive career.

If you’re interested in the full list of pitchers, check it out here