According to Wikipedia, Tommy John went to high school at Gerstmeyer High in Terra Haute, Indiana. I have to wonder how many pitches he racked up during those four years. Had he been pitching in high school today, he would have had to abide by Indiana’s state rules that a pitcher may not pitch more than 10 innings on three consecutive days. But had he been born in a state like Louisiana or Massachusetts, the sky would have been the limit.

Last month, a high school pitcher in Washington threw 194 pitches over 14 innings of work. In a single game. However, he got a no-decision for his efforts. His story is not unique. And that’s just in the United States. In Japan, starting three games in a row(!!!) after throwing a 232-pitch(!!!) outing a few days earlier just kinda happens.

In 2013, the American Sports Medicine Institute (ASMI, also known as the place where Dr. James Andrews works) put out a list of guidelines for youth pitchers that suggested, among other things, that youth pitchers limit themselves to 100 innings per year and that they refrain from doing any sort of pitching for a few months out of the year. They also list the official Little League limits (although it’s not clear whether they are explicitly endorsing these) that a pitcher between ages15 and 18 throw no more than 95-105 pitches in one game and that after throwing more than 76 pitches in an outing, he should have four days of rest.

What’s interesting is that whether or not those are the “correct” limits, they most certainly differ from the rules and regulations that most state high school athletic associations place on their members. I reviewed the regulations for all 50 states (PDF warning), where they were available. The most common rule was that pitchers could not throw more than 10 innings in the space of three days. Very few states (13) mentioned mandatory rest. Only one state incorporated the idea of a pitch count into its regulations, and 11 state high school athletic associations were either silent on the matter or left discretion to the principal of the school. There was no state whose regulations were as strict as the Little League limits.

There’s been a cottage industry of people trying to explain the uptick in 2014 of pitchers who need Tommy John surgery that has popped up lately. ASMI put out a much-read position statement on the matter, which read in part, “Thus in many cases, the injury leading to Tommy John surgery in today’s young pro pitchers actually began while they were adolescent amateurs. Observations by orthopaedic surgeons support this link, as the torn ulnar collateral ligament (UCL) in a pro pitcher usually looks like it has worn out over time.” (Emphasis is mine.) Their position statement included several warnings for adolescent pitchers on how to avoid a visit to the orthopedic surgeon.

Is their position credible? Can we find evidence that pitchers who endure overuse as youngsters are more prone to be on the operating table as major leaguers?


(Thanks to my wife for the Father’s Day present.)

The biggest problem with running a controlled experiment on this subject is that we have no database of pitch counts from pitchers in their high school days. How many pitches did Brandon Beachy throw in high school? We don’t have exact counts. What we can do is make some reasonable assumptions. We’ll have to limit ourselves to pitchers born in the United States, and because there’s no database of where pitchers went to high school, I’ll have to assume that a pitcher went to high school in the state in which he was born. We’ll also assume that the state regulations on pitchers that are currently in place have been in place for a while. This isn’t a perfect set of assumptions, but it’s about the best we’re going to get on the matter.

I looked at whether each state had any codified limits at all for high school pitchers, whether those regulations included mandatory rest, and what the maximum weekly workload could be for a pitcher. In some states, that maximum workload is spelled out on the weekly level. In Maryland, it’s expressly set at 14 innings. In California, it’s 10 innings. In North Carolina, the rules dictate no more than 12 innings over 3 days. In theory, a pitcher could pitch four innings each day, and over seven days, could log 28 innings. It’s not to say that pitchers did pitch that sort of workload growing up (although, given that they were probably all the best pitchers on their high school teams, it must have been tempting), but that this can be used as a proxy for how liberal a state is in its pitch restrictions and the sort of pitching environment that was the basis for a pitcher’s development.

I pulled out the database that I used for this article on predicting pitcher injuries from last year. It includes injuries sustained over the time period of 2002-2012 from our own BP database for pitchers in the major leagues. I looked only at starters and checked to see what differences there were for certain types of injury events, based on whether the pitcher hailed from a state that had any codified rules around pitch limits or not.


State has no regulations

State has regulations

Spent time on DL*



Shoulder Injury



Elbow injury*



Had Tommy John surgery



* Chi-square is significant

Now, we look at whether the state mandated rest after long outings or after a certain number of days pitched in a row.


State has no mandated rest

State has mandated rest

Spent time on DL



Shoulder Injury



Elbow injury



Had Tommy John surgery



None of those came out significant, although the DL trip was close (p = .096). It’s worth noting that in all cases, pitchers from states with more lax regulations were more likely to get hurt.

I also ran four logistic regressions using the max workload variable to try to predict each of the four injury events above. Again, states that had more lax regulations produced pitchers who were more likely to go on the disabled list and to have elbow injuries.

In my original article on predicting injuries, I looked at several other co-occurring variables. For example, I looked at various performance metrics (K rate, BB rate), batted ball tendencies (GB rate, FB rate), and physiological (age, BMI) and historical (pitch count last year, pitch count to date) factors, along with control variables for whether the pitcher had sustained an injury to the same part of his body in the previous year. (A previous injury to the same body part was, by far, the best predictor of future injury.) This time, I re-ran those same regressions adding the codes for whether or not states had regulations for pitch limits and what the shape of those regulations was.

Even after controlling for all that, the question “Do you come from a state that has pitch limits?” is still a significant predictor of elbow injuries, although not Tommy John surgeries. However, one thing that we do know is that the best predictor of needing Tommy John surgery is having had a previous elbow injury. This isn’t a smoking gun, but it’s hard evidence to support the ASMI position and it needs to be taken seriously.

An Uncomfortable Question About an Inconvenient Truth

This exercise was prompted by a conversation I had with Sam Miller, in which he asked me what I would do to address the Tommy John epidemic. I said that it probably starts with strict pitch limits and rest requirements in high school baseball (and yes, college baseball as well). That is, after all, if we really are interested in preventing injuries. Is that what we’re interested in?

The obvious conclusions of this research are these: While we don’t have direct proof from these data that overusing pitchers at early ages makes them more prone to injuries later in life, we can call this indirect proof and align this work with other work done by orthopedists who are suggesting the same thing. On a team level, whether you’re a fantasy or a real GM, if you’re worried about injury risk, you might want to look up where a pitcher hails from and whether that state has rules in place to protect pitchers in their formative years. If data are available as to how a pitcher was used back in his younger years, you might want to avail yourself of it.

Pitchers from un-regulated states were 63 percent more likely to have an elbow injury and 32 percent more likely to need Tommy John surgery in a given year than those from regulated states. The findings weren’t statistically significant for Tommy John surgery, but they were for an initial elbow injury, and that’s the no. 1 risk factor for becoming a TJ patient.

Those findings are still fairly robust when you control for a host of other factors. It seems hard to argue anything other than that unregulated pitch counts at the high school level are a significant contributor to injury risk for pitchers who get to the MLB level. The fact that I looked only at pitchers who manage to make it to MLB (because it’s what we have data on) ignores the possibility that some pitchers flame out in the minors before making it to the bigs. That effect might be lurking out there too, and we don’t have a way to formally study it.

You could look at the data one of two ways. One is to note, as I did above, that these pitching regulations do appear to have a real effect on preserving the health of a young man’s elbow. There probably are common-sense pitch counts and rest mandates that could be constructed that would reduce the chances that he would later on need Tommy John surgery. Another way is to say that while an increased risk of Tommy John surgery is not a good thing, the effect size in an absolute sense was a change of one percentage point. While it’s statistically significant, it’s probably not visible to the naked eye.

Then there’s this. Remember the pitcher who threw 194 pitches in 14 innings from the intro?

That pitcher, Dylan Fosnacht, is an adolescent male who has been raised in the “win at any cost” culture of masculine America. In Washington, where the game took place, there is no pitch or inning limit per game. Under the regulations, Fosnacht would have been required to rest for two days after his outing, but his 14-inning stint was completely legal. If he were to make the majors, it seems fairly obvious that his marathon outing would have at least some effect on his future chances at health. In all likelihood, however, Fosnacht will never pitch professional ball, because most high school pitchers do not go on to pitch professional ball, even at the minor league level, much less the major leagues. (In fact, Fosnacht isn’t a full-time pitcher.) Even if we could make the case that overuse practices increase the likelihood of Tommy John surgeries by 10 or 20 percentage points, the reality is that most pitchers will never get to the majors for that to even matter. (And for what it’s worth, Tommy John isn’t usually a death sentence. It isn’t 100 percent successful, but the success rate is in the 80 percent range.)

If the goal is to reduce the number of major league pitchers having Tommy John surgeries, there are probably some usage restriction policies that we can make a reasonable case would do the trick. The ASMI guidelines seem like a good place to start, and any individual pitcher who wants to preserve his arm for future paydays would do well to follow it. But of course, that means that he would be taking himself out of important games and not playing as much on the “showcase circuit.” Y’know, the place where all the scouts are. The incentives to go beyond the “safe” levels of usage would be huge. Plus, in heat of a state championship tournament, it’s not like coaches and players are primed to make optimal decisions about a player’s future 10 years from now. The entire culture of baseball is aligned to go against the ASMI recommendations.

The limits would have to be imposed by state high school athletics associations. The cost of that would be that a coach wouldn’t be able to maximize his resources to win games in the here and now when frankly, the here and now is all most of these kids will ever need to worry about. Suppose a coach has a pitcher who is good and obviously the best on the team. He’s not and never will be big league good, but he gives the team a chance to win every game he pitches. You’re taking a shot at glory away from a bunch of these kids nationwide, maybe the only shot that they’ll ever have in baseball, just so that a half-dozen or so lucky guys who eventually do make it to the majors later in life won’t need TJs (and sportswriters will have fewer fits.)

You could make the case that high pitch counts are setting a pitcher up for an increased risk of elbow problems for life in general, but no one ever phrases the question that way either. But the uncomfortable question that no one seems ready to answer is this: What exactly are we trying to do? No matter how you answer that, someone will be mad. If you keep regulations lax, there are incentives for coaches to overuse the good pitchers, including most of the ones who will eventually have a chance at the majors. Hopefully coaches who realize that they have something special on their hands would practice a bit of restraint, but some are better at restraint than others. And their overuse will probably cost a few pitchers several million dollars and perhaps even the chance at any career at all, not to mention a bum elbow for the rest of their lives. If you tighten the regulations up, in addition to all the moaning about state over-involvement and meddling paternalism, there’s the very real chance that you’re taking away the best chance that a team had because a bunch of writers had a sad when Jose Fernandez paid a visit to Dr. Andrews.

So yeah, we probably can do something about the Tommy John epidemic by intervening at the high school level. The question is whether the price is something that you’re willing to live with.