Fastball Velocities Are Already Up

Early-season baseball analysis can pose challenges. While it’s fun to consider a world in which Yermín Mercedes is the best player in baseball, we know that this level of performance will not stick in the long run. That can make early-season analyses of players premature, as we need data to begin stabilizing before drawing firm, player-specific conclusions. Luckily, however, league-wide data stabilizes much faster, especially when we put league data in its proper monthly context — acknowledging that April baseball and July baseball are, in fact, different. That’s why it’s fascinating to analyze early season league-wide fastball velocity.

Given how much we at FanGraphs have discussed fastballs lately, it might be time to start calling us FastballGraphs. In all seriousness, there has been some excellent discussion about the fastball here on the site, with both Tess Taruskin and Kevin Goldstein covering the pitch. Taruskin made note of young prospects who threw harder in spring training, while Goldstein underscored the importance of the pitch’s shape. Today though, I’ll be focusing on velocity in the season’s early going.

So far, in 2021, pitchers are throwing hard. Through games on April 7, more than 15,000 fastballs — four-seamers, two-seamers, sinkers, and cutters — have been thrown, with an average velocity of 92.7 mph. On the surface, that might not be eye-popping, but if that holds, it would represent an April record in the Statcast Era. In fact, since 2015, no April or May has ever featured a league-average fastball velocity over 92.5 mph:

Further, 92.7 mph is rare for a league-wide fastball velocity reading even later into the season. As velocities have increased over time, we’ve seen more months of 92.7-plus, but it’s worth noting that not once during the 2017 or ’18 seasons did major league pitchers throw as hard in a single month as they are throwing now. Only seven of the 30 months in the above table saw the league-wide fastball velocity hit 92.7 mph.

Of course, if league-wide fastball velocity is increasing, then it must be increasing on an individual level as well. And it is. Consider: Just over a full week into the season, 85 different pitchers have thrown a fastball harder in 2021 than they did during the entirety of the 2020 season. Here are the hurlers with the largest difference in maximum fastball velocity year-over-year:

This list is filled with interesting names. At the top, we see players who are returning to full health, like Foltynewicz, Holmes, Ohtani, and Doolittle. Further down the list are players like Bundy, who was throwing noticeably harder even during spring training. And, of course, there are guys like Davis, who has struggled with declining velocity in recent years but might have found something left in the tank.

But the sheer fact that we have 85 different pitchers who have already surpassed their max pitch velocity from 2020 is pretty fascinating. And it’s not like we’re dealing with a small sample phenomenon, either. It would be pretty easy to surpass your maximum fastball velocity in 2021 if you only threw one fastball in 2020, but of the 85 pitchers to break their 2020 highs, 68 threw at least 100 fastballs last year. Right out of the gate, pitchers are throwing much harder this season, and that’s something we’ve been able to observe at both the league-average as well as the individual level.

This might not be totally surprising, given that we’re coming off of what was the weirdest year for baseball everyone in recent memory. For pitchers in particular, their preparation was thrown off, with MLB halting play due to the pandemic in the middle of spring training, before returning for a brief summer camp and a 60-game sprint to an expanded postseason. What a whirlwind it was.

But, among the many ways in which the 2020 season impacted the game, what it also did was throw off the ramp-up period for pitchers. Even after a month of spring training, fastball velocities don’t peak until the middle of the season, where they then typically plateau through the rest of the year. This is represented pretty well when we evaluate the change in league-wide fastball velocity relative to April from 2015 to 2019:

By May, pitchers typically throw fastballs 0.2 mph faster than they do in April, and by June, they typically throw 0.4 mph faster. Things settle in after that, as the month-to-month fluctuations from June through the rest of the season are by no more than 0.1 mph.

As a result of the shutdown, pitchers did not have the opportunity to ramp up. That’s why, in 2020, velocities were actually down a touch. From Opening Day through the end of August, pitchers averaged 92.5 mph on the fastball, while in September, they averaged 92.6, both of which were down year-over-year compared to the same month in 2019. Rather than ramping up during the course of a season, pitchers spent April through most of July throwing on their own. (There’s also Alvarado (notably near the top of the table), who told Matt Gelb of The Athletic that, instead of throwing, he ate too much of his mother’s cooking.)

Perhaps it’s not a surprise, then, that fastball velocities are up compared to 2020. But they’re up even compared to 2019, and with further ramp up, we very much could see the average fastball velocity for a month hit 93.0 mph for the first time. Pitchers are throwing harder than ever before, and even though we’re analyzing all the other ways pitchers can fool hitters with the fastball, it’s important to remember that velocity is still king.