Time of Reckoning: Who Loses the Most in a Pitch Clock World?

I have never been supportive of pitch clocks. In fact, the first ever thing I wrote about baseball (formally), was an article in the Journal of Sports Sciences, illustrating how pitch clocks could elevate muscle fatigue in pitchers, possible contributing to increased injury risk. I also came up with a workload metric which factors in the time between pitches when calculating the number of Fatigue Units a pitcher can accumulate. I was pleased to read Travis Sawchik’s article on pace of play solutions, focusing on how it may be more on the batters than the pitchers when it comes to speeding up the games. Well, I was pleased until the last paragraph, where he proposed the ol’ 15 second pitch clock – but we’ll get there.

Despite evidence that suggests Pitch Clocks will not actually help the game in any substantial way, MLB keeps bringing them up as the golden ticket to solving pace of play issues.

The paper I published relied on predicted fatigue levels, and was essentially a modelling exercise. While the models were extensively tested, and empirically validated, there is always some concern when applying these types of findings to living, breathing pitchers. Thankfully, Yang and colleagues conducted a similar study in 2016, and found a 12 second pitch clock, compared to a 20 second pitch clock, would lead to lasting fatigue effects days after a pitching performance. If I sound like I’m beating the same drum over and over again, it’s because evidence is being ignored.

But blah blah blah, scientists are giving warnings. It’s 2017, that doesn’t mean anything anymore. What impact might this have on pitchers?

Using Fatigue Units, what influence would possible Pitch Clock rules have on pitcher workloads?

The PitchF/X data can be a bit noisey, so I had to make a few assumptions to the database. This included making some modifications and some assumptions to pace data. I calculated the average pace per inning by looking at the time of the last pitch, and the time of the first pitch every inning. Then, I divided this total time in seconds by the number of pitches thrown. If a pace was less than 10 seconds, I set the value to that of the 10th %ile value from 2017 – to 21.3 seconds. If a value was greater than the 90th %ile pace (27.5 seconds), I set the value to 27.5 seconds.

To simulate the effect of pitch clocks, I reduced the maximum time value by approximately 5% (26.5 seconds) to simulate the 20 second clock, and to 25.5 seconds to simulate the 15 second pitch clock. Both of these are not very accurate with respect to the proposed pitch clock time – but take into account, if someone is on base, the clock is turned off. Furthermore, Jon’s tweet up above shows that the paces are not really influenced significantly by the pitch clock. So, instead of using 15 seconds, or 20 seconds in the pitch clock conditions, I reduced the 90th %ile time by 5% to reflect the 15 second pitch clock condition, and 4% to represent the 20 second pitch clock condition.

Now that the paces were defined, I calculated Fatigue Units for the 2017 regular season. Setting a minimum of 500 pitches thrown, who would have the greatest change in their workloads?

Simulated Pitch Clock Influence on Workloads
Rank Name Pace (from FG) Fatigue Units (self) Fatigue Units (20 PC) Fatigue Units (15 PC) Change from Self to 20 PC Change from Self to 15 PC Inning Appearances Pitch Total
1 Aaron Bummer 21.5 5.90 7.38 7.66 125.15% 129.83% 59 897
2 Silvino Bracho 27.3 3.89 4.70 4.87 120.73% 124.93% 36 550
3 Dan Jennings 26.8 16.58 19.39 19.99 116.97% 120.57% 170 2607
4 Boone Logan 24.2 6.79 7.89 8.12 116.25% 119.65% 57 801
5 Chase Bradford 25.1 6.72 7.80 8.04 116.18% 119.70% 37 549
6 Alex Wood 24 12.00 13.64 14.03 113.66% 116.93% 64 952
7 Dustin McGowan 24.5 15.72 17.82 18.33 113.40% 116.62% 162 2637
8 Keynan Middleton 27.6 14.79 16.61 17.05 112.27% 115.28% 61 971
9 Zack Greinke 24.7 16.10 18.05 18.55 112.11% 115.21% 103 1344
10 Jerry Blevins 26.7 12.99 14.56 14.98 112.07% 115.35% 137 2177
11 Pedro Baez 31.1 17.50 19.55 20.04 111.71% 114.56% 182 2673
12 Heath Hembree 26.4 15.23 17.00 17.47 111.58% 114.70% 151 2377
13 Josh Hader 23.7 8.37 9.33 9.60 111.53% 114.75% 50 667
14 Cory Gearrin 29.8 13.62 15.13 15.55 111.08% 114.19% 57 829
15 Addison Reed 22.4 18.88 20.95 21.52 110.99% 114.01% 100 1082
16 Matt Albers 26.3 14.21 15.77 16.19 110.98% 113.95% 139 2282
17 Cam Bedrosian 29.9 8.73 9.68 9.95 110.93% 113.95% 61 966
18 David Hernandez 25.6 11.52 12.78 13.12 110.90% 113.83% 105 1795
19 Chris Smith 24.5 6.57 7.27 7.45 110.71% 113.47% 62 1044
20 Rex Brothers 28 4.88 5.40 5.55 110.64% 113.67% 40 652
21 Juan Minaya 24.7 10.82 11.97 12.30 110.62% 113.66% 48 652
22 Ryan Tepera 28.4 19.84 21.94 22.46 110.58% 113.20% 209 3025
23 Joe Kelly 29.4 13.73 15.16 15.58 110.39% 113.47% 54 881
24 Sergio Romo 27.4 11.40 12.56 12.88 110.21% 113.00% 124 2015
25 Mike Dunn 28.6 13.13 14.47 14.85 110.21% 113.08% 73 1024


Ok let’s get this out of the way – this is a real Bummer of a list. Moving on. To be noticed on here is the fact that only 2 starting pitchers appear in the top 25 of most impacted pitchers – Alex Wood at number 6, and Zack Greinke at number 9. Increased workloads are associated with increased risk of injury, and given Alex Wood’s history, the pitch clock isn’t going to do him any favours.

The rest of these pitchers are all relievers. Given the findings from Travis’s article on pitcher pace, this isn’t really shocking. However, knowing what we know about injury trends, particularly for Tommy John Surgery, relievers are at a higher risk of injury. The Pitch Clocks would impact them the most.

I am not arguing there are no ways that we could speed up the game. In fact, I’m all for pitchers throwing pitches in quicker succession – but, this has to be because the pitcher feels they are ready to throw, and not because they are forced to throw. In the field of ergonomics, we use a technique called psychophysics to determine when a worker feels they could perform an action without an increased level of fatigue, or risk of injury.

Forcing pitchers to throw when they have not fully recovered is going to lower velocities, and possibly lead to an increased of injury. Pitchers will become more fatigued, a known risk factor for injury, if pitch clocks are used. Speed the game up, but don’t do it at the expense of pitchers. If the pitch clocks are enacted, fantasy owners should expect reliever volatility to continue to rise.

Full list of pitcher workloads and simulations of pitch clocks

Ergonomist (CCPE) and Injury Prevention researcher. I like science and baseball - the order depends on the day. Twitter: @DrMikeSonne

Newest Most Voted
Inline Feedbacks
View all comments
6 years ago

So what happens if the clock expires? Does the batter get issued a ball?

6 years ago
Reply to  Mike Sonne

This has probably been mentioned by other people elsewhere, but I just realized that this could be a way that managers (infrequently) drag out the clock more. If you want to intentionally walk a guy before bringing in your next reliever, have the pitcher putz around for a minute and a half so the guy in the pen can keep warming.

6 years ago
Reply to  bder19

Or what if a guy like Bartolo, who doesn’t generally walk many guys, just decides to take his time, motion to the home plate umpire and give the batter a ball.

6 years ago
Reply to  bder19

Managers can do that now. There is no reason a team can’t give an intentional walk the old-fashioned way by throwing 4 wide ones. I was actually surprised that I never saw that this year. Seems like an easy way to buy your reliever a half dozen extra tosses.