An expert on biomechanics and a team source talk about their approaches to evaluating and managing pitcher workloads.
For today's article on impervious and not-so-impervious pitchers, I got my David Laurila on, speaking to Glenn Fleisig of the American Sports Medicine Institute—whose name is almost always followed by the phrase, "the world's foremost authority on biomechanics"—and to a scouting executive from a major-league club (affectionately and frequently referred to in the article as "the executive"). Both had a lot to say, and not everything they said fit into the article. One of the things I failed to fit in was their extended perspectives on pitcher workloads and the efficacy of innings limits, so I'm rectifying that by posting both takes here. Dr. Fleisig comes first, followed by the team official.
Turning the caution dial back to make for a better-informed pitcher usage patterns.
When Baseball Prospectus was first getting started more than a decade ago, we ended up helping add a certain pointedness to the question over what sort of workloads starting pitchers could handle by creating a statistic, Pitcher Abuse Points. Controversial at the time because of the inference that it was a predictive tool, what PAP was in fact was a counting stat, sort of like a warning light on the dashboard of your car-it gave you cause for concern, but it wasn't telling you that a complete breakdown was incipient. However, when PAP was first published, the baseball industry was perhaps better typified as relatively indifferent on the subject. Previous warnings about workloads had been aired-perhaps most famously in Craig Wright's and Tom House's The Diamond Appraised in the '80s-but generally speaking, pitcher workloads weren't as carefully monitored as they are now.
Fast-forward a decade, and that has changed almost industry-wide. Organizations monitor their pitchers from the highest level to the lowest, count pitches in games, on their throw days, warming up in the bullpen, even throws to the bases, if it involves a pitcher and a baseball in flight, it's being charted. In A-ball leagues, several teams use adaptive workloads with an eye towards keeping younger pitchers from being overworked-instead of a normal starter/reliever split in assignments, you'll find groups of pitchers pitching in tandem, paired off to handle the first six or seven innings together, and throwing 60 to 90 pitches, and trading off the honor of starting or following in that ballgame. As much as possible, teams are not sacrificing any of their pitching prospects for the greater glory of pennant race in Binghamton.
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It's accepted wisdom that the beatings of backstoppery impact player performance, but by how much?
"What's to get tired from? This isn't like football or basketball. Even if you play 100 games in the outfield, you handle only six or eight balls a game. What can wear you out? It's hard to get physically tired in baseball, unless you pitch or catch."
"Get up. Get down. Get up again. Get down. Come up throwing. Take the chest protector off. Take the shin guards off. Hit. Put them back on. Go back behind the plate and repeat the process. Catching just breaks a man down, inning by inning, game by game, year by year."
One of the glaring weaknesses in the injury analysis game is the lack of data. As the injury database is built and populated, we are left with spotty research and anecdotal knowledge, especially when it comes to the crossroads of sports medicine and pitcher workloads. Adding to the problem is the lack of data for both minor league and college pitching. Since pitching is pitching, opponents of workload limitations often bring this up.
In one of the first systematic studies of early pitching workload, Lee Sinins, creator of the Sabermetric Baseball Encyclopedia, studied 135 pitchers who threw 175 innings or more before the age of 22.
In one of the first systematic studies of early pitching workload, Lee Sinins, creator of the Sabermetric Baseball Encyclopedia, studied 135 pitchers who threw 175 innings or more before the age of 22. Age 22 is equivalent to the age-point found in Nate Silver's study on pitcher injury and age--the Injury Nexus--but was selected by Lee prior to the publication of Nate's study. Lee selected the pitchers from The Sporting News 1997 Baseball Register, giving us a distant enough perspective on many of the pitchers and allowing objective analysis on the possible effects of heavy workloads at such a young age. Unfortunately, innings thrown in winter leagues or in spring training could not be counted in this study as the data were not available. Innings were not adjusted for level and the totals are a sum for all levels in a season.
There were a few basic theories being tested in this study. First, the injury nexus would be tested. Despite the strong correlations between age and injury found by Nate Silver, real world numbers should match up closely. Second, while somewhat arbitrary, the 175-inning threshold seems to be a point where fatigue sets in for almost all pitchers. Young pitchers usually have not reached this threshold in their careers and the first test of this level often results in injury, massive failure, or a survivor effect.
Two years ago, when we first introduced Pitcher Abuse Points, pitch counts
were still shrouded in a veil of mystery. They were available, mind you,
but they were squirreled away at the bottom of box scores, and rarely
ventured from their hiding place to appear in game summaries or in
televised accounts of the game. Columnists never brought them to our
attention. Livan Hernandez could throw 140 pitches in utter obscurity.
Today, ESPN tracks Rick Ankiel's pitch counts the way CNBC tracks
Injuries to pitchers are not a new phenomenon. They date as far back as the
rule change that allowed pitchers to throw overhand, and so do the attempts
to restrict the workload of pitchers to a safe level.
Other than the teeth-gnashing fringe element of bitter Reds fans mourning
the rise and fall of Jon Nunnally or Dmitri Young or Willie Greene, has
anyone else noted how much Jack McKeon is using some of his relievers?
Through the first 54 games of the season, side-armer Scott Sullivan
is on a pace to toss 133 innings. Touted rookie Scott Williamson
projects to throw 109 innings, and erstwhile co-closer Danny Graves
is on his way to 123 frames.
Baseball Prospectus introduced Pitcher Abuse Points
last summer as an attempt to measure the workloads of
starting pitchers. Briefly, the system is based on the premise that each
pitch above a certain threshold is incrementally more damaging than the
last, with the damage growing more severe as more pitches are thrown. Our
threshold is 100 pitches; beyond that, a pitcher "earns" one
point each for pitches 101-110, two points each for pitches 111-120, and so
For more on the system, please check the
original PAP introduction