Fastball Foundations: Starters Dominating with their Primary Fastball
A trip through fastball strike rates to see which pitchers are having the most success with their primary heater.
I wrote this same post last year, but I wanted to bring it back around for 2025. We’re looking at four-seamer strike rates. A reminder about how Strike% is calculated:
Strike% = (Called Strikes + Whiffs + Foul Balls) / Total Pitches Thrown
Before we get started, we also want to know what’s good. The league average Strike% on a four-seamer is 49% this year.
The question then is WHY. Why do we care about this? Personally, I think it gives a guy an actual chance at being a consistent starter in the league. Over the last past few years of doing this, I’ve seen so many pitchers unable to deliver results consistently because their fastballs suck. There’s more to pitching than just a fastball, of course, but this is the foundation of pretty much every consistently dominant pitcher I’ve seen.
It’s also correlated with WHIP. Here’s a re-used graphic from last year:
Not a super strong correlation, but it’s something. It’s something. Earn strikes with your most commonly used pitches, and oftentimes, good things happen.
So let’s go through the top several names on the list. I’ll show you the best names regardless of ownership rates, but we’ll be sure to hit some guys who are available in your leagues right now along the way.
FF Strike% Leaders Overall
Requiring at least 200 four-seamers thrown this year, here’s what we have in an interactive table from Data Wrapper. The % column is what percentage of the time that pitcher throws their four-seamer.
If you want to filter it to just the starters, you can require 500 four-seamers minimum. Here’s a screenshot of that from my main Tableau dashboard.
The SPs at the top of the list are mostly unsurprising. Hunter Greene, Zack Wheeler, Kevin Gausman, Joe Ryan, Spencer Schwellenbach, etc. Most of these guys you would expect to be there, and you already knew they had great fastballs.
But let’s dive into a few names quickly.
Eury Perez, Marlins (56.7% Strike%)
We’ll see if he can keep it going tonight in Cincinnati. Since Eury didn’t pitch last year, it’s possible that some people out there aren’t super familiar with him. But he was a hugely touted prospect a few years back, and it looks like he’s mostly back to his former self after the long time off. It might be a little too early to say that, but it’s certainly true that he should be owned and started in every league right now.