Poor Tommy John: Ruining baseball's future

Thank you to the Tommy John Surgery Data, which provided all data used in this article!

When Tommy John injured himself in 1974, he was out indefinitely. Nobody knew what was happening & no doctor was able to fix it. Tommy John (TJ) was not a high performer but a stellar contributor across his 26 years in the league. The “Bionic Man” started a revolution in the sport of baseball, which heavily impacts it today: he heavily bruised his elbow & got it fixed.

When mentioning Tommy John Surgery today, friends of the national pastime show a disgusted face & grumble something like “looking forward to see him next year!”. What requires the procedure in the first place is the rupture of the ligament in your elbow (similar to the knee), which is then replaced by something from somewhere else of your body. As you might not from any MCL/ACL injuries, it takes time to train them & it is the same for your elbow.

Why is this a problem though? Football pitchers & skiers break their legs over the years, and they are fine (they are not, different topic), right? Technically this also applies to baseball, although the rate of it happening is alarming. Tommy John would normally occur to pitchers only (the people throwing 160+ kph balls at you), as they overflex their elbows to execute their pitches (throws) with a maximum of velocity & break. Yet, currently, the system breaks with the highest share of athletes needing Tommy John being 15 to 19 years old (see here).

Especially at this young age, having underdeveloped muscles & core, the pipeline for pitchers dries up faster than initially planned. This furthers thins out the number of pitchers available throughout the minors & major league, which is becoming increasingly difficult. Pitch count is the main metric coaches consider when replacing starting pitchers & bullpen arms. Looking at the age of pitchers getting TJ surgery, a worrying trend can be seen:

Despite a recent uptick, the trend towards early TJ surgery was in decline, where the median age in 2000 was 24.2 years and bottomed out at 21.98 in 2016 (9.17% drop). It drifted back to normal in recent years. Nevertheless, the constant rise in TJ surgeries is alarming, being close to triple of what it was 20 years ago (29 to 94). A key ingredient backing up this up is the general level when pitchers get their first TJ surgery, which goes from college as a majority up to the big leagues.

When putting this further into perspective of the two key major levels with TJ surgeries, we can clearly observe that reversal happening:

Especially in the early 2024 season, MLB already reached the TJ levels of the past years, with the season just starting. Most of the changes on a college level can be traced back to the athletics department setting a higher priority on preventing elbow injuries through easy pre-season programs & less wear in games.

When considering the minor league system, we can relate to the COVID times & the disproportionate number of wear & tear players’ aftermaths, as the minor league season was drastically reduced early on:

Minor league injuries are at lower levels, especially compared to the number of total players in the system: Considering the ±270 players in a minor league system per club & the 40-man roster in MLB, the likelihood of a TJ injury for one of the ± 14 pitchers is 4.62x likelier (5.083% vs. 1.098%).

But what can we do? Nothing. Especially offspeed pitchers are prone to TJ & will stay, given the extreme horizontal & vertical movement of pitches. Recent years were a success nevertheless, focusing more on pitch prevention (staying below 100 pitches) as well as the introduction of less intense off-speed pitches overall (hello sweeper!). Overall, it might be best to start pitching the knuckleball again. Story for another day.