How many innings can one arm throw?

According to Beckett is thinking about retirement.

Beckett needs surgery to repair a torn labrum and a lesion in his left hip, whether he pitches again or not.


He’s a high-mileage 34-year-old, having thrown 2,051 innings in 13 big league seasons.

I don’t doubt Beckett might decline a four-month rehab, as the article suggests is needed. He hurts, he’s made more than $116M in his career and has a couple of small kids, so why not retire? Other than the no-hitter this year I suspect he hasn’t had much fun this season. He even says “It takes four hours of [therapy] work to do two hours on the field.”

I think baseball may have seen the last of Josh Beckett as a player. But that bit about his innings pitched raised a question for me — is 2,051 IP high-mileage? Over 13 years he’s averaged 209 IP over a 162-game period. He was a full-time starter when he was 22 years old. Among Dodger starters:

  • Dan Haren is 33 and has thrown 2,202 innings in 12 MLB seasons for a 162-game average of 215 IP.
  • Kevin Correia is 34 but has thrown only 1,397 MLB innings for a 162-game average of 168 IP in 12 seasons.
  • Roberto Hernandez is 34 with 1,248 MLB innings for a 162-game average of 190 IP over 9 seasons.
  • Hyun-Jin Ryu is 27, has 7 years of Korean League experience and 1,269 innings there in addition to the 336 he’s got in the big leagues, averaging roughly 178 IP (the Korean Leagues throw off the 162-game calculation).
  • Chad Billingsley is 30 and has 1,175 MLB innings for a 162-game average of 195 IP over 7 seasons (and 12 innings).
  • Kershaw, believe it or not, is 27 but has 1,349 MLB innings himself and has averaged 223 IP over a 162-game period in 7 seasons.

Of the three guys who are the same age as Beckett, Haren’s the closest in hard use. He’s always been a starter. Correia pitched his first five years in relief and as a spot starter. Hernandez was a full-time starter in his second year in the bigs.

If Beckett is high-mileage, then Haren, averaging 215 IP, and Kershaw, averaging 223 IP, are the two guys who could also be classified as such. We can only hope Kershaw doesn’t injure himself throwing that many innings every year.

15 thoughts on “How many innings can one arm throw?

  1. Nice writeup on,, pointing out Haran’s success this year. Yes, he’s had the stretch that was soo bad, but he’s also won a dozen games.

    The recap pointed out something I missed (the scoring innings were spent with me on the phone trying to get my Internet connection fixed) — the offense once again needed the pitcher to come up with a big AB.

    If anyone has the time, it might be worth comparing pitchers’ and catchers’ ABs — not just for RBIs and runs scored, but for being a positive part of scoring (getting on base or moving the runner(s) along). Since this is Vegas, I’d be willing to bet the ratio favors the pitchers more for the Dodgers than any other team. (Which, of course, is as much a reflection on the poor catchers at the plate as it is the strong batting pitchers, especially Kersh and Zack — I believe even Ryu had a couple of key doubles.)

    • I can recall 2008, when Dodgers pitchers hit .128 compared to the PH Mark Sweeney who hit .130.

    • How about this, the oWar of the three catchers is -0.8 and that of Kershaw, Greinke, Ryu, Beckett and Haren is 1.6. So, yeah.

        • Wins that their bats/running have accounted for above that of the theoretical AAAA player.

          • I’m impressed by the stat: that they’re able to figure it out AND specific results with LA.

            Can two players get credit for the same run? Someone gets a basehit but the runner scores when not expected (e.g. a Puigian scamper home from 2nd on an infield hit) — or just the runner because he made it happen?

          • Its a theoretical construct. There is a formula for what goes into scoring a run and how many are needed to garner a win which is used to measure the value of their various activities toward that end.

  2. “We can only hope Kershaw doesn’t injure himself throwing that many innings every year.”

    Amen, Link! Hopefully Kersh’s build allows him to be more of an iron man.