Starting Pitcher Fastball Velocity Decliners — Apr 7, 2021

Yesterday, I listed and discussed the starting pitchers whose fastball velocities have increased by at least 1.5 MPH versus 2020 during their first starts. This is an early indicator of a breakout, though it requires this new higher velocity level to be sustained. Let’s now move to the fastball velocity decliners. Just like the surgers might not sustain those gains all season, don’t panic just yet about these decliners. Velocity does bounce around from start to start and early in the season, it’s possible these pitchers are still building up their arm strength. However, these are big holes to climb out of, so these could be early signs of a disappointing year.

Luis Castillo endured a surprising epic meltdown during his first start. Not only did he last just 3.1 innings and allow eight runs, but he failed to strike out any one of the 21 batters he faced. This from a pitcher who struck out over 30% of batters last year. Turns out, he sits atop the velocity decliner list, so this may not have just been a bad day. He averaged less than 95 MPH in starts during 2017 and one time in 2019, so this isn’t the first time, but it’s a pretty rare occurrence. We haven’t heard a word about his health after the start, which is a bit of a surprise given his struggles and velocity drop. I’m eager to see what happens during his next start, but I would already be concerned if I were an owner.

After a superb six starts last year, Elieser Hernandez was a popular sleeper heading into the season. His velocity, which wasn’t very good to begin with, was down during his first start, and sure enough, he’s landed on the IL due to biceps inflammation.

It was anyone’s guess what we’d get from Corey Kluber this year after he has pitched just 36.2 innings over the past two seasons. Welp, the early returns aren’t good, as his average first start velocity sat below 90 MPH. Kluber’s secondaries have always been strong and are the reason he has been elite in the past, but you wonder how bad his fastball would have to get to dramatically cut into the effectiveness of those pitches. I’m not optimistic, unless his velocity returns.

This start tied for the lowest average velocity in a game for Walker Buehler, tying a late May start in 2018. That’s not good. His lowest velocity after 2018 came last year at 95.7, so this was a big drop from his 2019-2020 low as well. Buehler’s fastball has generated a double digit SwStk% over his career, which makes it pretty elite. But will this lower velocity cut into it? It’s likely. As someone who has thrown over 60% fastballs over his career, the velocity on the pitch would seem to be pretty important.

The excitement over John Means stemmed from his velocity jump last year, which led to a significant improvement in underlying skills (and SIERA) last year. Unfortunately, his velocity over his first start dropped right back to his 2019 level. I had mixed feelings on Means heading into the season, as he’s an extreme fly ball guy in a home run friendly park and even with the added velocity, only managed a 23.9% strikeout rate and 12.5% SwStk%. Now if he doesn’t get his 2020 velocity back, does he fall back to his 5.02 SIERA skills of 2019? Statcast confirms that he’s shown BABIP suppression skills, but it’s been over a tiny sample size, so we don’t know what his true talent level actually is, just that his low BABIPs so far are pretty much deserved. I’m still skeptical he could deliver value without the added velocity, as I am always hesitant to rely on a low BABIP.

The knock on Shane Bieber has been that he owns a “bad fastball”, so a drop in velocity ain’t good. Like Kluber, he owns elite secondary pitches, so he’ll certainly get by if his fastball is even worse. But “getting by” isn’t going to be good enough when owners bought him as a top three starting pitcher.

Yeesh, who knew there was actually an even lower gear to Kyle Hendricks’ fastball?! After a jump last year to its highest mark since 2016, Hendricks’ fastball has given back all those gains and then some. He’s used elite command to succeed with a low velocity fastball throughout his career, so I wonder how much he’ll actually be affected if his fastball stays at this level all year. I hate owning him because I keep waiting for things to quickly unravel, but that hasn’t happened yet. Is this finally the year? For my fantasy team’s sake, let’s hope not.

Though it didn’t translate into more strikeouts, Ryan Yarbrough’s SwStk% spiked last year, suggesting additional strikeout rate upside that hasn’t been forecasted. A velocity dip is going to make it much harder to accomplish, so perhaps he and Hendricks should get together and brainstorm how do get hitters out throwing their fastballs at just 85-86 MPH.

I was right about Kevin Gausman’s breakout last year, but that feeling was driven in part by a velocity spike. This year, his velocity has dropped back to his 2018-2019 level. That’s always the risk betting on velocity surgers, as you never know whether it will continue in the upcoming season. If Gausman remains at this level, he should still be perfectly acceptable in mixed leagues calling Oracle Park home, but his value is obviously going to take a substantial hit without all those extra strikeouts and the risk his ERA jumps back above 4.00.