Do pitching mechanics fail after 100 pitches? Is the effectiveness of a pitch diminished after 100 pitches?

Baseball personalities state that the threshold is arbitrary.

Veterans of the game cite that pitch counts coddle the pitchers too much, weakening their arms, and causing injuries.

Doctors, researchers, and sabermetricians state that large quantities of high leverage pitches can lead to injuries.

So, who is correct?

*An Innings Pitched challenge: Sound off in the comments below, prior to reading the article. Voice your opinion on pitch counts and then follow up, after reading the article, to see if your opinion has changed.*

**Sabermetric Collection of Data**

Let’s first talk about how Innings Pitched collected the already available data, from reputable sources, like FanGraphs and Baseball Reference.

- Identify metrics that are affected by fatigued arms
- Base-on-balls
- Strikeouts
- On-base-percentage
- Slugging percentage

- Identify pitches who threw a minimum of 195 Innings, in 2016
- Pull historical data for their entire careers
- Pitchers include the following:

- Examine metrics and separate into quantifiable groups
- Pitches 1-25
- Pitches 26-50
- Pitches 51-75
- Pitches 76-100
- Pitches 101+

- Generate an MLB average, for each pitch count range, and per each metric
- Compare to Nolan Ryan’s (1988+), Pedro Martinez’s, and Greg Maddux’s career averages

**Historic Baseball Pitcher Selection**

The three pitchers selected for comparison were strategically selected.

Nolan Ryan has consistently been an advocate of baseball pitchers throwing more.

“It’s because pitchers simply don’t throw as much as we did. That’s the real issue here. When I pitched, we pitched every fourth day and guys would pitch 300 innings and it wasn’t considered a big deal. If you don’t get on the mound and develop stamina, you’re risking injury.

This whole thing with the 100-pitch count limit— I have a real problem with that. Pitchers are all different and when you put standard limitations on them, you’re not utilizing their talent.” – Nolan Ryan

Pedro Martinez, was known for his epic meltdowns after throwing the 100th pitch. The pitch count was center stage during Game 7, of the 2003 World Series. Grady Little went against the statistics and left Pedro Martinez in, against the New York Yankees. The Boston Red Sox lost the game, and Grady Little was ultimately fired for the debacle.

Finally, Greg Maddux, was a control artist, and perennial workhorse. He pitched more than 200 innings 18 times from 1986 to 2008.

**Sabermetric Evaluation**

Pitching mechanics deteriorate as baseball pitcher fatigues. The pitcher will lose their release point or their front hip will open too early. Each mechanical deficiency can result in a missed pitch location (ball or left out over the plate). Base-on-balls can increase (or decrease if more pitches left over the plate), strikeouts can decrease, on-base-percentage, and slugging percentage can increase.

Base-On-Balls

Innings Pitched tallied up the total number of starts per pitch count range.

For example, if Max Scherzer threw 75 pitches in one start, and gave up three base-on-balls. Innings Pitched pulled data that depicted that 2 base-on-balls occurred between pitches 1-25, 0 base-on-balls between 26-50, and 1 base-on-ball between 51-75. The 2 BB’s were divided by 1 start = 2 BB’s for pitches 1-25. This exercise was repeated for every baseball pitcher with the data set and for every category of pitch count. The results were then graphed.

A few outliers exist in the above image: Matt Moore, of the Tampa Bay Rays and San Francisco Giants (orange), and Mashiro Tanaka, of the New York Yankees (yellow). However, on average, a nice cluster of data exists.

An average of all these values was taken to generate a trendline. The trendline was then graphed on a plot and compared to Nolan Ryan’s (1988+), Pedro Martinez’s, and Greg Maddux’s career statistics. Unfortunately, this type of data was not available for Nolan Ryan, prior to 1988. Something of note though is that Nolan Ryan’s base-on-balls per inning were actually higher from 1971 to 1980, than 1988 to 1993, so the comparison still holds substantial value.

The MLB averages, in the image above, hovered around 0.425 from pitch 1 through 100, with a major drop off after the 100th pitch. Now you may be asking, why are there less walks after the 100th pitch? The answer is simple. More pitchers are missing over the plate, compared to outside the strike-zone, leading to more contact. *The key here is the decrease in walks, after the 100th pitch.*

Nolan Ryan started off with a high walk rate, gave up less walks at the 51-75 pitch mark, and walked more at 76-100 pitches. *The key here is the decrease in walks, after the 100th pitch, which is similar to the MLB average.*

Pedro Martinez’s walk rate dropped significantly after the 75th pitch. Could this be where Pedro Martinez started to give up substantially more baserunners? More on that as we continue through the analysis. *The key here is the substantial decrease in walk rates, after the 75th pitch.*

Greg Maddux hovered around 0.30 to 0.35 walks per 25 pitch range, remaining relatively consistent throughout. *Therefore, no real correlation between pitch count and base-on-balls can be made for Greg Maddux.*

Strikeouts

The same exercise and calculations were repeated for strikeouts per 25 pitch range.

The range in the image above varies drastically here (0.4 to 1.80 per pitch count range), but minus a few outliers the trend follows a pretty standard path. There are less strikeouts pitches 1-25, slightly more strikeouts between pitches 25-50 and 51-75, and a drop-off thereafter.

The 2016 American League Cy Young Winner, Rick Porcello of the Boston Red Sox, is the lowermost green line. Corey Kluber of the Cleveland Indians, is the dark red line at the top. Chris Sale, formerly of Chicago White Sox, is the uppermost blue line.

Similar to the base-on-balls exercise, a trend-line of the average strikeout rates per pitch count range was generated and compared to historical, Hall of Fame, baseball pitchers.

The MLB average starts around 1.26 strike-outs for pitches 1-25 and increases to approximately 1.44 for pitches 26-50. From there, a gradual decrease occurs from pitches 51-100, with a substantial drop off from 1.21 to 0.6, after the 100th pitch was thrown.

Nolan Ryan’s strikeout rates decreased from the 1-25 to 26-50 pitch mark. Then increased again until the 51-75 pitch, before gradually decreasing at a relative linear rate from 76 pitches to 101+ pitches. *The key here, is the strikeouts decrease, after the 75th pitch.*

Pedro Martinez’s strikeout rates dropped emphatically after the 75th (or the 51-75 pitch count range). His strikeout per 25 pitches dropped from 1.89 to 1.19 from 76 to 101+ pitches; roughly three-quarters of a strikeout less per 25 pitches, than his first 75 pitches. *The key here, is the strikeouts decrease substantially, after the 75th pitch.*

Greg Maddux’s strikeout trends, mimic that of the MLB average. A large drop-off occurs after the 51-75th pitch mark (or once the 76th pitch is thrown). The drop-off is from 1.23 at the 75th pitch to 0.65 over 100 pitches.* The key here, is the strikeouts decrease substantially, after the 75th pitch.*

**Sabermetric Analysis, Mid-Point Wrap-Up**

We have gone through a lot of data thus far, so let’s have recap the findings we have made so far.

Base-On-Balls

- MLB Average,
*base-on-ball rates drop-off of cliff after the 100th pitch mark, after remaining steady for pitches 1-100.*- Nolan Ryan:
*Base-on-balls dropped significantly, after the 100th pitch* - Pedro Martinez:
*Base-on-balls dropped significantly, after the 75th pitch.* - Greg Maddux:
*No real correlation between pitch count and base-on-balls can be made*

- Nolan Ryan:

Strikeouts

- MLB Average,
*strikeout rates drop off substantially at the 101st pitch mark, after gradually decreasing from the 51st.*- Nolan Ryan:
*Strikeouts continually decrease, after the 75th pitch.* - Pedro Martinez:
*Strikeouts decrease substantially, after the 75th pitch.* - Greg Maddux:
*Strikeouts decrease substantially, after the 75th pitch.*

- Nolan Ryan:

**Sabermetric Evaluation, Continued**

On-Base-Percentage

Innings Pitched had an easier time pulling together on-base-percentages, against a particular baseball pitcher. No calculations were required, just a graph.

The first thing that will jump out at you, in the above image, is the dark blue line. This line represents, Jerad Eickhoff of the Philadelphia Phillies. The sample size of Jerad Eickhoff throwing more than 100 plus pitches is small (8 times), but since he pitched 195 innings or more in 2016, his data was part of our analysis. The Philadelphia Phillies should take notice and not let Eickhoff throw more than 100 pitches, for the foreseeable future.

*Minus Eickhoff,* the MLB league average on-base-percentage has nice data cluster around .300.

The MLB average starts around .307 OBP for pitches 1-25, decreases to .295 for pitches 26-50, .298 for pitches 51-75, .306 for pitches 76-100, and .297 for pitches 100 plus. *The key here is small (slightly statically jump), after the 75th pitch mark.*

Nolan Ryan’s OBP against decreased from the 1-25 until the 76th pitch. The OBP substantially increased (0.068 points), during the 76th -100th pitches. He was worse than the MLB league average at between 76-100 pitches. The OBP then decreased (improving) after the 100th pitch. *The key here, is the major increase in OBP, after the 75th pitch mark*.

Pedro Martinez’s OBP against increased emphatically after the 100th pitch. However, the OBP against, was still less than the MLB average. *The key here, is the major increase in OBP against, after the 100th pitch mark.*

Greg Maddux’s OBP against increased gradually, after the 50th pitch. Around the 76-100 pitch mark, Greg Maddux’s OBP against matched league average. After the 100-pitch mark, Maddux was worse than league average in OBP against. *The key here, is the gradual increase in OBP against, after the 50th pitch, but more importantly the larger incremental increase after the 75th pitch.*

Slugging Percentage

Innings Pitched had an easier time pulling together on-base-percentages, against a particular baseball pitcher. No calculations were required, just a graph.

Similar to OBP, the first thing that will jump out at you is the dark blue line. This line represents, Jerad Eickhoff of the Philadelphia Phillies. The Philadelphia Phillies should, once again, take notice and not allow Eickhoff to throw more than 100 pitches, for the foreseeable future.

*Minus Eickhoff,* the MLB league average on-base-percentage has nice data cluster around .375 slugging-percentage.

The MLB average starts around .394 slugging percentage for pitches 1-25, decreases to .365 for pitches 26-50, increases to .381 for pitches 51-75, increases to .402 for pitches 76-100, and then decreases to .358 for pitches 100 plus. *The key here is in gradual increase in slugging percentage starting after the 50th pitch.*

Nolan Ryan’s slugging percentage against, decreased from the 1-25 until the 75th pitch. The slugging percentage then substantially increased (0.061 points), during the 76th -100th pitches. The slugging percentage then relatively plateaued, thereafter. *The key here, is the major increase in slugging percentage after the 75th pitch, although still below league average.*

Pedro Martinez’s slugging percentage against, linearly increased after the 50th pitch. However, the slugging percentage against were still less than the MLB average. *The key here, is the gradual increase in slugging percentage against, after the 50th pitch.*

Greg Maddux hovered around 0.370 to 0.341 slugging percentage against, remaining relatively consistent throughout. *Therefore, no real correlation between pitch count and slugging percentage can be made for Greg Maddux.*

**Sabermetric, Three-Quarter Point Wrap-Up**

Let’s wrap up the on-base-percentage and slugging percentage, similar to the mid-point wrap up.

On-Base-Percentage

- MLB Average:
*OBP against increased slightly, after the 75th pitch mark.*- Nolan Ryan:
*OBP against increased significantly after the 75th pitch mark.* - Pedro Martinez:
*OBP increase significantly after the 100th pitch mark.* - Greg Maddux:
*Gradual increase in OBP against, after the 50th pitch, but more importantly the larger incremental increase after the 75th pitch.*

- Nolan Ryan:

Slugging Percentage

- MLB Average:
*Gradual increase in slugging percentage starting after the 50th pitch. Peaked after the 75th pitch.*- Nolan Ryan:
*Major increase in slugging percentage after the 75th pitch, although still below league average.* - Pedro Martinez:
*Gradual increase in slugging percentage against, after the 51st pitch.* - Greg Maddux:
*No real correlation between pitch count and slugging percentage can be made.*

- Nolan Ryan:

**Sabermetric Analysis, Final Remarks**

The table below will help decipher and correlate all these findings together in one place.

Examining, the results.

- MLB average, base-on-balls against, decreases after the 100th pitch.
- Nolan Ryan has similar stats
- Pedro Martinez, base-on-balls against, decreases after the 75th pitch

- MLB average, strikeouts decrease after the 75th pitch.
- Nolan Ryan, Pedro Martinez, and Greg Maddux, all follow the same path.

- MLB average, on-base-percentage increases after the 75th pitch.
- Nolan Ryan, OBP against, increases substantially after the 75th pitch.
- Pedro Martinez, OBP against increases substantially, after the 100th pitch.
- Greg Maddux, OBP against increases earlier, after the 50th pitch.
- MLB average and Nolan Ryan, decrease in OBP after the 100th pitch.

- MLB average, slugging percentage increase after the 50th pitch.
- Nolan Ryan, slugging percentage against, increases after the 75th pitch
- Pedro Martinez, slugging percentage against, increases after the 50th pitch.

**So what does all this tell us about the pitch count?**

**Sabermetricians are correct**, *with an asterisk**.

If a baseball pitcher is able to get past the 76-100 threshold, there can be a path to additional success. However, on the whole the 76-100 pitch threshold, is where nearly every statistic is against the pitcher continuing any further (i.e. pull the pitcher at the 75 pitch mark).

This idea can be related to number of times through the batter ordering. Generally speaking, OBP and Slugging Percentages increase each time through the order.

Fans and commentators should take note. This research effectively shows why the short outings of the starters in post-season play works so well. The data also makes Andrew Miller’s role even more invaluable and shows that the concept of bullpening an entire game can be extremely beneficial.

**No baseball pitcher should throw more than 75 pitches to remain highly effective**. Otherwise, the numbers are against you.

Was your initial stance on pitch counts changed?

Future Research

- Correlate pitch count findings with number of times through batting order.
- Identity baseball teams and baseball pitchers who consistently violate this mantra, and cost themselves games in the process.
- As command/fx data becomes more readily available, correlate a fatigue arm with a missed pitch location.

Check back in the future, for completion, of the additional research.

This is my initial thoughts, prior to reading. We’ll see how it changes.

1. Having a pitch count isn’t arbitrary, but 100 being the threshold is both arbitrary and overgeneralized. It assumes that all pitches are created equal, ignoring mechanical efficiency) effort level, pitch type, stress, how many innings the pitches were divided into, pitcher build, arm resiliency and a billion other factors that vary from pitch to pitch and pitcher to pitcher.

2. Even if you show that pitchers are less effective/more fatigued after 100 pitches, it’s a self fulfilling prophecy – pitchers fatigue after 100 pitches because they’ve been trained to go 100 pitches

Now off to read the article.

I’m back!

First, great article.

My opinions above haven’t really changed, but they are now more informed and well-cultivated.

A couple observations:

1. The OBP jump from 51-75 to 76-100 might be statistically significant, but it’s not significant within the context of a baseball game. The average game sees each team send about 40 batters to the plate per game. A .008 jump in OBP would allow an extra batter to reach base about 1 time every three games – and that’s if that OBP spike was over the course of a full game, rather than just from pitches 76-100.

Rough napkin math here, each team generally throws about 150 pitches per game, meaning pitches 76-100 is roughly one sixth of the game. Multiplying that by about 40 batters per game, we’re talking about approximately 7 batters coming to the plate during that time. That means the OBP jump equates to about 0.05 extra batters reaching base, or about one every twenty games. In other words, leaving pitchers in pitches 76-100 costs a team about eight baserunners per year. That’s pretty insignificant, and likely trumped by the benefit of saving your bullpen.

Not to mention that the OBP jump is mostly attributed to Eickhoff. What would the trend line look like with him removed? It wouldn’t be much of a change at all

2. I would attribute the walk rate falling after pitch 100 to the fact that pitchers only get left in after 100 when pitching well

3. Why did you use K and BB per start instead of per BF?

Josiah, great comments and feedback!

Glad, the article provided insight.

While I agree that the OBP change may be insignificant, especially when removing Eickhoff. That is not the only argument.

Slugging percentage does increase at the same interval. I wish we had more information on hard contact per pitch count. I think that information would tell you that the ball is hit harder as the pitcher fatigues. This could also show why the OBP normalizes, since softer hit balls tend to increase BABIP, compared to harder hits ones. But, inherently the damage can be greater for harder hit balls.

I chose not to utilize Batters Faced, since some of this can get lost. There can be statistical noise from bad fielding, bad defensive positioning, or simply bad luck with BABIP.

I agree that the walk rate could fall off after the 100 pitch mark due to a pitcher throwing well, but it could also be because a batter has seen so many pitches from the pitcher at that point. Likely, they have a semi read at that point.

Your points will fuel some future articles!

Slugging does go up, but slugging on pitches 76-100 isn’t really higher than 1-25, which calls into question whether fatigue is what we’re really seeing here or if it’s some combination of other factors

That is the beauty of statistics, so many different ways to piece them together for interpretation.