Are Pitchers Getting Better at Holding Their Velocity?

More than anything else, I’ll remember Carlos Rodón’s no-hitter for how it ended. Not when he hit Roberto Pérez in the foot — that was no fun, but perfect games end on nonsense all the time — but because he threw harder as the game went on, topping out at 99 mph on his 110th pitch of the game. It’s all the more impressive when you consider that he started the game in the low 90s.

Pitchers losing velocity as the game goes on is a phenomenon as old as baseball itself. That’s just how it works; throwing a pitch requires a ton of physical effort, and doing it 100 times will wear you down. If you’ve ever done repetitions of anything in your life, you can empathize. Rodón laughs at that fact of life, in a way that I think of as Justin Verlander-esque, and I was curious whether other pitchers follow the same pattern, particularly after Jacob deGrom popped a casual 101 mph fastball in the seventh inning of his latest start.

Using deGrom as evidence of anything is an iffy idea at best — the man is a unicorn, a pitching deity descended to earth. But Rodón is mortal, and he does it, so it’s hardly some unobtainable goal. I set out to see whether pitchers are adding velocity in later innings these days, and whether that addition has changed over time.

First, I took each pitcher’s average four-seam fastball velocity on their 11th through 30th pitches of the game. Why the 11th through 30th? Eli Ben-Porat’s research established a counter-intuitive but strong pattern: pitchers generally throw softest on the first 10 pitches of the game as they ramp up their exertion. Thus, we’ll exclude those when looking for which pitchers throw harder as the game goes on — everyone throws harder as the game goes on if you include those first 10.

Next, we need a sample for “late in the game.” Ben-Porat’s research also shows that pitchers who pass 100 pitches tend to tick up in velocity — they’re emptying the tank, as it were, leaving it all on the field, and whatever other clichés you’d like to use there. With the finish line in sight, everyone throws harder. My cherry-picked Rodón example might not even be useful! Instead, I took the 71st through 90th pitches of each start to measure late-game velocity.

At this point, a leaderboard is in order. Thus far in 2021, 17 pitchers have increased their four-seam velocity as the game wears on. Good news for my lede, as well — Rodón heads the list:

In fact, he heads the list by a lot. Crismatt is on there due to an extended relief appearance, and he’s the only pitcher who increases their velocity by even half Rodón’s mark.

That interesting tidbit aside, this was more pitchers than I expected, and deGrom didn’t even appear — his velocity is basically unchanged, declining by 0.2 mph from early to late. In fact, 49 pitchers saw their velocity decline by 0.5 mph or less. That’s a huge crop of pitchers who appear to be immune to fatigue, give or take a half tick. Am I living in some past world of pitcher relative velocity?

To check on that possibility, I stopped looking at specific pitchers and instead went with an average. So far this year, the average pitcher has seen his fastball velocity decline by 0.8 mph late in games. There are interesting names at the bottom — Sonny Gray brings up the rear with a 2.7 mph drop, and times-through-the-order pariah Blake Snell checks in near the bottom with a 1.7 mph decline. In aggregate, though, I’m most interested in that 0.8 mph number.

As a comparison, I looked at pitchers of five years ago. I wanted to compare apples to apples, so I didn’t look at the whole year; it would be pointless to do this study and later find out that stamina is at its peak in April and spends the rest of the year declining. I took every pitch in March and April of 2016 and performed the same calculations as my 2021 sample on them.

In 2016, a whopping 30 pitchers gained velocity from early to late in games during the month of April. Justin Verlander, the patron saint of saving velocity for when you need it, appears on the list, but he’s hardly the only good pitcher; Max Scherzer, Adam Wainwright, Pirates-era Gerrit Cole, Masahiro Tanaka, CC Sabathia, and David Price all accomplished the same feat.

In fact, the 2016 sample of pitchers only saw their velocity decline by 0.6 mph as the game wore on. So much for new training being the differentiator; from this superficial check, at least, pitchers have been holding onto most of their strength for years now. That’s not to say that a 0.6 mph decline in velocity isn’t meaningful; several studies have found that throwing fastballs harder is better for the same pitcher — a great shock, I know. Tom Tango’s study, the third link above, approximated a 0.20 increase in ERA per lost tick of velocity for the same pitcher.

Perhaps, though, we should be looking at relative velocity decline as a predictor of which pitchers should have short leashes. Ben-Porat’s study asserts that velocity is one of the key determinants of times-through-the-order penalty. It’s hardly unbelievable that pitchers who lose velocity lose effectiveness, even if you think that familiarity also plays a role.

What’s more, losing velocity may be indicative of an overall loss of form — if your body can’t work at peak form when it comes to exertion, it would hardly be a stretch to think it also isn’t working at peak form when it comes to command. Perhaps we should be looking at velocity decliners as candidates for a quick hook rather than using a blanket everybody-out-of-the-pool management style.

Guess what? Snell appeared at the bottom of the 2016 list as well. He isn’t the poster boy for quick hooks for no reason. On the other hand, more pitchers than you think hold their velocity as the game goes on, and even though it might feel that way, it’s not a new effect. This merits more study, but let me leave you with two quick takeaways. First, maybe you shouldn’t be so upset with a quick hook if the pitcher in question is losing velocity. Second, gaining velocity as the game wears on isn’t impossible, and the pitchers who do it might not lose as much effectiveness as you’d think over the course of their outings.