For decades, the conventional wisdom around pitching injuries has been deceptively simple: pitchers get hurt because they throw too much. While there's an element of truth to this, a couple of recent articles lets us know that the age of simple pitch counting may not be great. Professional sports teams are replacing it with a more dynamic model of risk, where how and when you throw is as important as how much. This post will distill the 3 most surprising and impactful findings from recent studies that challenge what we thought we knew about keeping pitchers healthy.

Why Pitchers Are Throwing More Before Getting Hurt

When Major League Baseball introduced the pitch clock in 2023, many players and analysts voiced their concerns: less recovery time between pitches would surely lead to more arm injuries. The data, however, tells a different and stranger story.

A study by Card et al. that compared the pre pitch clock (2021–2022) and pitch clock (2023–2024) eras found no significant difference in the incidence of ulnar collateral ligament (UCL) tears. The rate was 0.63 injuries per 1000 innings pitched before the clock and 0.67 after, a statistically insignificant change.

The highlight of this study was that pitchers in the pitch clock era were able to endure a significantly higher workload before getting injured. Authors found that the average workload in the season of their injury was 45.7 innings and 721 pitches in the pitch clock era, compared to just 26.5 innings and 442 pitches in the pre pitch clock era.

To put it simply, pitchers were able to throw over 70% more innings and 63% more pitches in the season of their injury in the pitch clock era, which directly contradicts the simple "less rest equals more risk" narrative. One possible explanation is that shorter game times and reduced downtime between innings might keep a pitcher's arm warmer and more consistently prepared to throw, potentially creating an unexpected protective effect.

Why Official Pitch Counts Miss Half the Story

When we see a pitcher's final line of 6 innings and 100 pitches, we assume we have a full picture of their workload. Research shows this isn't even close to the truth. The official pitch count ignores thousands of "hidden pitches," all the throws made before a game, between innings, and in bullpen sessions.

A study by Erickson et al. on MLB pitchers quantified this invisible workload and arrived at a stunning statistic:

This means a pitcher's official 100 pitch outing represents only about half of their actual game day workload. But here's the kicker: despite this massive hidden workload, the researchers did not find a significant link between the number of hidden pitches and the likelihood of injury in MLB pitchers. This reinforces a theme we'll see again and again… simply counting more throws isn't the answer. The context of those throws (whether they are high stress game pitches or low intensity warmups) is paramount, a distinction that metrics like "innings pitched" completely ignore.

Why Innings Are a Terrible Way to Protect Pitchers

While most modern leagues have adopted pitch counts, some youth and amateur leagues still use "innings pitched" as the primary way to limit pitcher workload. Multiple studies have shown this to be a flawed and potentially dangerous metric.

The problem is that an "inning" is a measure of opportunity, not effort. A dominant pitcher might record three outs on just three pitches, while a struggling pitcher could labor through 30 or more pitches to get out of the same inning.

A study by Mair et al. on youth baseball leagues put this in stark relief. The league that used inning limits saw single game pitch counts soar as high as 135 pitches. Meanwhile, the league that used a pitch count limit (a maximum of 85) saw its highest single game total reach only 89 pitches.

Matsuura et al., which directly compared the two systems and their health outcomes:

• The inning limit group (max 7 innings) averaged 98.2 pitches per game.

• The pitch count limit group (max 70 pitches) averaged only 52.5 pitches per game.

• Crucially, the pitch count limit group had significantly lower rates of elbow pain (31.9% vs 40.9%).

The takeaway here is that relying on inning limits can unintentionally expose young pitchers to dangerously high workloads in a single outing, dramatically increasing their risk of pain and injury. While we value pitch counts and believe they're a helpful tool, they're just the starting point. Our focus is shifting from simple volume to the complex interplay of intensity, context, and cumulative stress. Simple rules of thumb are being replaced by a more nuanced, data driven understanding of what truly causes a injuries in a pitcher's arm.

For youth players especially, pitch counts are a good foundation, but having someone knowledgeable on your side who can help you make informed decisions about workload management adds tremendous value. As we continue to peel back the layers of what truly puts a player at risk, here is something to think about:

How will teams, coaches, and parents adapt their approach to prioritize long-term health in a sport so often defined by short term results?