Pitcher workloads have been decreasing on a linear path for the past thirty years, yet injuries are at an all-time high. What gives?

The situation has become particularly glaring in the past few seasons, a period in which workloads are at an all-time low yet arm injuries are skyrocketing. Consider:

Prior to the turn of the millennium, the 120-pitch start was a relatively common occurrence, taking place approximately 10 percent of the time. This rate actually marked a downturn from previous decades, but the trend line of high-volume outings has fallen off a cliff in the past 15 years, with the percentage of 120-pitch starts cutting in half between 2000 and 2001 and continuing to slide ever since, culminating in this season's paltry 1.4 percent frequency.

Interestingly, the average pitch counts per game throughout the league have held relatively stable over the past 25 to 30 years: In 1988, starters averaged 96 pitches per game, which is the same mean value as we have seen thus far in 2014. The average count of innings pitched per start has also held: 1987 starters averaged 6.2 frames per start, while today's pitchers are at 6.0.

The stark differences lie on the extremes, as teams have streamlined starting pitcher workloads to avoid the heavy-use outings that received such derision around the turn of the century. The variance in innings-per-start has been muted, particularly on the high end, as teams have essentially standardized their collective approach to pitcher workloads and eliminated the outliers. Starting pitchers have been aggressively capped in their per-game pitch counts, such that the 120-pitch game has nearly become extinct, and the 130-pitch game has become so rare as to invite automatic scrutiny whenever a hurler surpasses the threshold. Meanwhile, relief pitchers have been relegated to shorter stints as teams have expanded their bullpens and ushered in the era of specialty relievers.

Long relief stints were common 30 years ago, and in 1980 the average outing for a reliever comprised more than five outs. That number is down to 3.1 outs per appearance in 2014, as the game has moved toward LOOGYs, ROOGYs, and one-inning specialists. The frequency of relief outings that went above one inning was greater than 50 percent until 1988, and through 2004 it was more common for a reliever go more than three outs than less than three, but the sub-three-out appearances took over in 2005 and haven't looked back. The mound game has morphed from a long-distance run to a series of short sprints, and today's approach fits a paradigm of a six-inning starter who gives way to a trio of single-frame relievers.

What does this all mean, and how could it relate to injuries? After all, the sheer magnitude of pitches thrown is down for all types of pitchers, and the league-wide focus on protecting the game's fragile arms has never taken so much of the limelight. My contention is that today's pitchers are not being prepared to handle a heavier workload, and that the sprinter mentality (especially as it relates to the emphasis on strikeouts) has altered the physical reality for today's pitchers. Compounding the issue is that the current approach of putting all pitchers in fewer categories of workload ignores the fact that these are humans with very different profiles for stamina, mechanics, conditioning, and repertoire.

Pitchers are babied through the minor leagues, with strict innings caps and tandem-starter techniques creating a situation where some players face heavier workloads as amateurs than when they hit the pros. Pitch limits have also been instituted at the amateur levels to help protect younger arms, and though these restrictions have largely been a positive by preventing coaches from extreme cases of abuse, there is also merit to Nolan Ryan's stance regarding the downside of such limitations:

“I haven’t been pleased with the direction baseball’s taken pitching over the last 15 or 20 years, and I felt like we needed to regain some of what we had lost. I felt like we had a lot of pitchers that have been on pitch limits ever since Little League, and we don’t know what their genetic potential is as far as the number of pitches and workload they can handle.”

And from Rangers pitching coach Mike Maddux (in the same 2009 article): “Guys that train for a mile ain’t running more than a mile.”

The Ryan Express was certainly an outlier in this area, but he also understands what it takes to have the stamina to pitch for a long time with heavy workloads at the highest level. Today's pitchers are not being trained to withstand heavier workloads, and in fact their timid build-up in the minors puts these players on a path of increasing difficulty that continues once they hit the majors. We could interpret this as teams becoming complacent or just following the status quo, but Ryan outlined a major flaw in the current paradigm of pitcher development, and the crux of that flaw is a lack of recognition of the individual nature of pitching.

Consider the case of Jenrry Mejia, who was determined by the Mets not to be able to cut it in the rotation and who was thus transitioned to the closer role. I agree with the move out of the rotation, as there were several indicators that Mejia was ill-suited for the 100-pitch challenge. His delivery is low on stability and high on power, a dangerous combination that should be shielded both for the sake of injury and for performance. He also struggled to maintain velocity throughout the game, as evidenced by the following velocity chart from his final start of the season (back on May 9th):

However, turning Mejia into a 15- to 20-pitch reliever was a drastic adjustment from the 100-pitch expectations that he had in the rotation. Perhaps Mejia would be optimally utilized for 40 to 50 pitches at a time, allowing him to make the most of his repertoire and stuff without exposing him to added risk, but the accepted structure of the modern pitching staff leaves little opportunity to take advantage of such a pitcher.

There do exist pitchers who can withstand the rigors of 120 or more pitches, but the structure of modern-day pitching leaves no room to identify those players. The lessons of Pitcher Abuse Points have been well ingrained, but what is missing is the reality that PAP thresholds are different for every player. I wrote about this five years ago in “Arm Action,” using the examples of Pedro Martinez and Randy Johnson. Somewhat famously, Martinez was not the same pitcher once he got past the century mark, and my contention was that his PAP should start counting around the 90-pitch threshold in order to account for his profile. In contrast, Johnson would often throw 130-plus pitches with no ill effects, an ability that required a different baseline for PAP in order to understand the actual risk for his particular case.

Johnson and Martinez represented another case of extremes, but they illustrate the idea that individual pitcher profiles for stamina and injury risk can be very different. There is still some variation among starters in today's game, but the workload distribution has been greatly narrowed, and with it have disappeared the options for teams to optimally utilize their individual pitchers. Pitch count limits can be a positive, but the way they are utilized today has acted to retard the development of some pitchers while tasking others with more than they can handle. As Ryan mentioned, we lack the means to identify those pitchers whose genetic potential is greater than the current system will allow, while others are being forced into roles as 100- or 20-pitch hurlers rather than having their individual profiles dictate optimal usage patterns.

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Great article, Doug, with some outstanding points. Pitchers don't all fit into the same box, and individual tailoring seems far more commonsensical then insisting that one size fits all. Particularly for relievers.

I wonder though if part of the reason for the increased number of injured pitchers is because there are just more pitchers overall. There were 4 less teams in 1988, and I don't recall many 7 man bullpens - certainly not 8. Pretty sure there are more minor league teams now, too. I haven't looked at the nuembers, and I'm not entirely sure how to account for the minors, but it seems like a question worth raising.

Lots to think about in here!
Good article. Beyond pitch counts, there is today's five-man rotation compared to the four-man that was common until the 1980s. As Bill James once said, if you are taking eight starts each from your best, second-best, third-best and fourth-best pitch and giving those 32 to your fifth, there better be an upside -- and given the rising number of injuries, I am not convinced there is. During those four-man days, guys like Ryan and others would pitch 300 or more innings a year. No one has done that since Steve Carlton in 1980. Now, the league leaders are in the 230 to 250 range.
With all of the heat and big time sliders coming out of bullpens these days, I think a lot of teams see little need to have pitchers go much beyond 100 pitches. I think that contributes a lot to why guys aren't going as deep.

Still, I wish that teams would get out of this group think mode and innovate on pitch counts. 100 is an arbitrary number and has little to do with what an individual pitcher can handle. As Doug said, some guys should probably get cut off at 80, others at 120. At the same time, guys in the minors should be training to build up their pitch counts like a marathon runner builds miles. Instead, they do the same thing every game all season, then the team jumps them up the next season to a new pitch count. You wouldn't do that type of training in any other sport, because it doesn't make any sense. You're not going to run 5 miles once a week for a year, then all of a sudden bump to 10 the next year without ever building up towards that.
And thanks Doug for the always excellent work.
Here's an article I had to read twice because I didn't realize it quoted you, Doug:

I guess my question is "How many ways are there for a pitcher to injure himself pitching?" My guess is four(?): breakdown/traumatic injury due to short-term overuse (heavy pitch count), breakdown due to long-term overuse (succession of starts or seasons of heavy use) (these two obviously interdependent), throwing with high-risk mechanics, and throwing too hard for a pitcher's body to handle.

Now the only of these risks that has measurably increased over the years is velocity, right? Pitch count and innings both trend downward. And I'd assume that if we're lucky enough to have a Doug Thorburn at BP, MLB teams have likewise put more talent into mechanical analysis, and so even if on the N=1 level, some guys aren't improving, league-wide, it gets better.

So the only league-wide variables to deal with are velocity & workload; how hard they're working, & how long they're doing it. Is it possible that for all MLB teams' hand-wringing about pitch count, velocity increases are the real culprit, and that lower pitch counts, which allow the starter to reach back for his best stuff because the modern bullpen has his back, actually might put *more* stress on arms, if velocity is found to be more stressful than pitch counts, or at least underratedly accounted for? Can one measure how velocity & injury risk correlate? I guess in my head there's some unknown (& variable, based on body type, mechanics, starter-vs-reliever, etc) terminal velocity at which any human arm would explode, & as the average pitcher approaches that ceiling, injury risk increases exponentially. Now I'm going to comb the Thorburn archive looking for articles on injury risk, glad this is a long train ride.
I'm betting that the telling data point would be the average speed of fastballs. It's probably up 2-4 mph even since 2000, and certainly since 1985. Any way of figuring that out?
That's my thought, and not necessarily just fastballs. Kids today, as a collective, come up throwing harder now than they did 20-30-50 years ago. The radar gun means everything today. That, along with the increased number of pitchers in general, would seem to be two of the most "obvious" reasons behind the number of injuries...
Do you think in part, that support for this is the rising number of TJSs?
I think there are two things, more breaking balls, which usually put more strain on the elbow(the common injury of today), and as the two above have stated, velocity. I think it can also be tied to the rising strikeout numbers, which as I last heard have been record breaking every year the last two or three years.

95% of relievers throw in the mid-90s or better and have a wicked breaking ball.

80% of starting pitchers seem to be throwing 92/93+ and again lots of breaking balls. Felix Hernandez is becoming somewhat famous for his high breaking ball ratio, despite a very good low to mid 90s fastball(with movement).

Pitch counts are useful tool, but they are not an unbreakable law. Good managers respond flexibly to new situations; mediocre managers stick to safe formulas. Good pitchers pace themselves, and don't throw every pitch as hard as they can.
Pitchers today are taught to throw as hard as you can as long as you can. What could go wrong? There's plenty of guys in the bullpen.

The modern way of using pitchers guarantee that most pitchers, especially relief pitchers, lose a large proportion of their throws in the bullpen. This produces a vicious cycle that burns out pitchers and creates a need for more and more pitchers.

There's no sure-fire way to prevent pitcher injuries, but the way we're doing it now blows out their arms.
How would a young pitcher, or even a minor leaguer, go about establishing his pitch threshold? Is it a certain amount of pain felt? A certain percentage drop in velocity? The number of days until the arm is fully recovered after an outing? And once established, does it remain constant? How often would a player or organization assess this threshold?

And is candor over discussing pain/soreness another problem here? Pitchers are supposed to be dragged off the mound, not inform a manager when he's starting to feel pain. And can all pitchers even tell what their threshold is? Matt Harvey claimed last season that his arm felt just fine, until it didn't, but some accused the Mets of overworking him, insinuating that they missed some signals.
I think there's something interesting in here that should be developed much further: IP *variance* for starters has actually decreased. I note that Carleton's study found that IP had some significance (though small) predicting injury, while no variant of pitch count really did (other than pitches > 120. Come on, at this point the evidence for that one is pretty clear and there's no reason to ever let any pitcher go over this point ever again, I don't care if Nolan Ryan used to throw 300 pitches every day up hill both ways in the snow). If IP is the significant injury contributor (i.e. get up/sit down cycles), lower variance might lead to increased risk - throwing 6 IP each time is more dangerous than 3 IP half the time and 9 IP half the time perhaps? (maybe this example is extreme)

I did a (extremely) half-assed computation real quick and found that innings pitched per *starter* (not per starting pitcher) have been essentially constant since about 1987 (save the strike-shortened years). (there was a surprisingly sharp drop off from before that point, at least relative to 1977 - didn't want to go too much farther back since there's so much expansion over a few years) But a plausible narrative emerges: starting pitchers throw a similar number of innings over the last 20-25 years, but distributed more narrowly such that pitchers get up/sit down a risky number of times/game more frequently per season, and with ever-increasing velocity. As these are both injury risks, their effect matches or supersedes the benefit of reduced number of times throwing extreme pitch counts. That's Gladwellian at best, but perhaps a starting point for someone less busy/more competent than I to examine scientifically...
Several thoughts here.

1.) Nolan Ryan was a freak. n = 1. We shouldn't use him as an broader indicator.

2.) Velocity and command are two different things and should be treated as such. Most baseball people will tell you command goes before velocity does. ...

... Which leads me to 3.) 100 isn't actually an arbitrary pitch count. There are specific points at which say, a Pedro Martinez becomes an Al Nipper. For Pedro, 100 was right about the mark at which he ceased being future Hall of Famer and started being Journeyman Pitcher. This threshold may vary slightly/somewhat depending on the individual, of course, but all the talk of pitch counts seems focused on (risk of) pitcher injury instead of (diminishing) pitcher effectiveness. If the goal is still to win the game, the latter needs to be higher profile in these discussions.

P.S. Doug obviously began the discussion of 2. and 3. above, and should be credited as such.

P.S. I liked the article.