I’m looking for data.... I often and frequently run pitchers out down to 70% and manage the effects of fatigue so that their effect is negligible. However, I recently have seen a trend that has me thinking the actual effect of the different types of pitching fatigue may not be the same.

I have statistically observed that a pitcher at 70% from appearance fatigue has not seen an increase in fatigue effects severe enough to be unmanageable. And often run pitchers out at this level and have never had reason to be concerned about them being fatigued.

However, anecdotally, I’ve seen a major drop off in performance from pitchers who are at or above 70%, but at or below 75% from pitch fatigue (thrown too many pitches on season).

I’m also curious about early-season fatigue and in-game fatigue, but these are harder to control and isolate % on...

If anyone has a team that has pitchers pitching at 75% or below, I’d be really interested in saving the game logs for those pitchers. If you could link to your team or league below and let me know which pitcher(s) I should be looking at, I’d appreciate it.

I'll have preliminary results once the few seasons I'm working through wrap up, but I think some of these results will be shocking. Especially the appearance fatigue factor. I don't think it quite works the way any of us thought and I'll have to do more experimenting with it in particular. How many consecutive games (to start the season, end the season, or anywhere in between) do you think it's possible to keep a pitcher at 100%? In the green?

After one team in particular, I can say the answer to all of those questions is astoundingly higher than I thought. Like, orders of magnitude higher, than I thought possible... I think it might even be possible if you control for certain conditions to keep a pitcher in the green all-season with them appearing in all 162 games (as a pitcher).


After pitching in the next game: