How Fast Can They Throw?

Velocity is king.

That idea, perhaps more than any other, has driven the evolution of modern baseball. Major League fastballs are faster than ever and getting faster. You already know this but I’m going to show you the data to drive home the point:

Baseball Savant

The league average fastball in 2008 was 91.1 MPH. Last season, it was 93.1.

Over that span, the fraction of fastballs thrown above 95 MPH has steadily grown and fastballs that don’t crack 90 seem headed the way of the Dodo bird:

Baseball Savant

In 2008, 12.2% of fastballs were thrown 95 MPH or greater. That share has more than doubled to 28.6%. Relatedly, 34.1% were thrown 90 MPH or below in 2008, compared to about 15.6% last year.

Follow the Leader

Velocity at the very top of the scale has become more commonplace, too. There were 214 fastballs clocked at 100 MPH or better in 2008. Last season, pitchers threw 3,367 such heaters.

This is not a trend driven by a small handful of superhumans, either. Aroldis Chapman may have broken the modern mold, like Nolan Ryan, Bob Feller, and Walter Johnson did before, but in recent years more and more pitchers have followed that lead and shown capable of throwing very hard:

Baseball Savant

The number of pitchers who threw at least one pitch measured 95 MPH or greater has increased by 75% since 2008 and the number of pitchers clocking 100+ MPH has more than tripled in the same span.

Last season, 64 different hurlers crossed the century mark, led by the Twins’ Jhoan Duran’s 391 triple-digit four-seamers. Duran also led baseball in average fastball velocity at 100.8 MPH and was one of just two pitchers (Seattle’s Andrés Muñoz 100.2) to average better than 100.

Because It Works

The motivation for all this peak velocity is obvious – it’s really hard for batters to hit. Just take a peek at how hitters perform against fastballs at higher velocities:

Baseball Savant

Velocity leads to more swings and misses and suppresses production on contact. The league slugs almost 200 points less against 100+ MPH heaters than those in the low-90s. A big reason why is that it’s very difficult to elevate high velocity – fastballs over 100 MPH that are put in play average just a 4.6° launch angle, whereas the other three bins in the table above average between 11.7° and 13.3° launch angles.

That combination of swings and misses and on-the-ground contact means elite velocity gives pitchers more margin for error with their location. To illustrate that, just watch this PitchingNinja compilation of all the 102+ MPH heaters that were located middle-middle last season. They yielded zero hits:

At the same time, the league’s rates of pitches in the strike zone (between 47.6% and 49.0% annually) and walks allowed (between 7.6% and 8.9%) have held steady since 2008, throwing cold water on the claim today’s high-velocity pitchers aren’t pitchers, but merely lower skilled throwers.

The Fastest Ever

After a late September Twins win in which Duran fired a fastball that showed 104 MPH on the broadcast (103.8 MPH by Statcast) community member BH-Baseball wondered how high velocity might climb and inspired this article.

It seems reasonable that there is some upper limit to human physical capability, but what might it be?

Back in his rookie season in 2010, Chapman threw a 105.8 MPH fastball that remains the fastest pitch recorded in the pitch-tracking era. He added another seven pitches at 105+ in 2016 and owns the eight fastest pitches tracked since 2008. The Cardinals’ Jordan Hicks is the only other player to have reached 105 in that span, doing so twice in one game in 2018.

While it’s generally accepted that today’s Statcast technology is the most accurate measurement system in baseball history, there are some who dispute whether Chapman’s feats really are the fastest ever. Many of the previous attempts to measure the fastest fastball are detailed in the 2016 documentary Fastball.

Ryan’s fastball was tracked by nascent radar technology in a 1974 game as part of a California Angels’ promotion, and one ninth-inning offering (as he was approaching 150 pitches) was measured at 100.8 MPH.

At issue, though, is that Ryan’s measurement was thought to have been made about 10 feet in front of home plate, not out of his hand as pitches are measured today. Pitches naturally lose speed as they fly because of drag, which means that Ryan’s fastball may have measured quite a bit faster out of hand. Estimates by Carnegie Mellon physicist Gregg Franklin suggest that Ryan fastball may have been upwards of 108 MPH.

A similar retroactive calculation exercise has also been done for Feller, widely accepted as the hardest thrower in the 1930s and 1940s. Feller had pitches tracked by equipment used by the Army to measure the velocity of ordnances, and one was measured at 98.6 MPH at home plate. That extrapolates to something perhaps as high as 107.6 out of hand.

Feller had also taken part in a gimmicky 1939 speed test that pitted his fastball, thrown in a shirt and tie, against a police motorcycle and resulted in claims of 104 MPH.

Johnson became what’s believed to be the first pitcher to have his fastball measured, clocking one at 122 feet per second (a little more than 83 MPH) in the Remington Arms Company’s testing room in 1912. That test was chronicled in the December 1912 issue of Baseball Magazine which made sure to note that Johnson could surely throw faster than that because he was not fully warmed up.

Baseball Magazine, December 1912, accessed from: LINK

Whether you take Chapman as the record holder or buy into the previous attempts made to measure pitch speed (count me as skeptical of those), an overarching takeaway of this section is that peak velocity may not have moved upward for some time. Despite all the new pitchers throwing very hard, no one has bested Chapman’s 105.8 mark, let alone come close to the claims about Ryan and Feller.

The Upper Limit?

Perhaps we have already reached the human limit for throwing a baseball. That’s what Dr. Glenn Fleisig, a biomedical engineer who runs the research department for the American Sports Medicine Institute (ASMI) in Birmingham, Alabama believes. Speaking with Baseball America’s J.J. Cooper in 2020, Fleisig said:

“It would totally shock me (if someone is throwing 107-108 mph in a decade). It would surprise me if maximum velocity goes up at all when compared to today.”

“Velocity is very sexy,” Fleisig said. “People are in love with the radar gun . . . The maximum velocity that baseball pitchers can pitch is essentially not going to go up. What’s going to change is the ceiling is not going to go up, but it’s getting more crowded at the ceiling.”

Kyle Boddy, the former minor league pitching coordinator for the Cincinnati Reds who founded Driveline Baseball, one of the industry leaders in promoting velocity and data-driven training techniques shared a similar view:

“I could be wrong on this. I’m thinking peak velocity won’t increase much, but a 100 mile per hour fastball will be commonplace”

That’s essentially what all the data I showed at the beginning of this article suggests has been happening. The very top has not seemed to move, but more and more pitchers are getting near it. Duran is a perfect example of that, throwing a huge fraction of his fastballs over 100 MPH but not seriously threatening Chapman’s maximum.

Ligaments Are The Physical Limitation

Perhaps the biggest reason why the upper limit has not moved much over time is that for all the training and strength gains pitchers can achieve, their velocity will be capped by the amount of force their tendons and ligaments can take without tearing apart:

Fleisig said, “In your arm you have bones, muscles, ligaments and tendons. The ligaments and tendons are not what is making you throw a ball. The ligaments and tendons are keeping everything attached . . . The ligaments and tendons are the weak links.

In an interview with Robbie Gonzalez of Wired Magazine in 2018, Fleisig explained the force that those tendons and ligaments – notably the elbow’s Ulnar Collateral Ligament (UCL) that is well-known from Tommy John surgery – endure when a pitch is thrown:

By studying cadavers, he and his colleagues found that the force required to tear elbow ligaments is roughly the same as what a pitcher asks of his arm throwing at top speed. When the arm flings back, the shoulder ligaments experience about 100 Newton meters of torque. When it flings forward, the elbow ligaments suffer the same. “It’s the equivalent, at each point, of holding five 12-pound bowling balls,” Fleisig says. “So imagine I hang 60 pounds from your hand. That’s what it would feel like on your elbow or shoulder.”

This GIF from Driveline illustrates the points in the pitchers’ delivery where that maximum torque is occurring:

Driveline Baseball : LINK

Training to Optimize for Velo and Health

Ligaments from cadavers are not the same as those in elite athletes, but they do establish a useful understanding of the general limits of the human body. Unfortunately, at least for now, we are not able to do much to train those tendons and ligaments, which get limited blood flow, to better hold up to the stresses of pitching.

Your ligaments and tendons get a little stronger, while your muscles get much stronger. So unless we can figure out a way to make ligaments and tendons proportionally stronger, you can’t push the body forward.”

“We can improve pitching mechanics, which we have done. We can improve nutrition and rest. We can improve available strength. What we can’t do is strengthen ligaments and tendons,” Fleisig said.

One of the things implied, then, is that pitchers who approach their maximum velocity are at greater risk of injury because of the increased force going through their shoulders and elbows. One of Fleisig’s studies, completed in 2018, suggested velocity training programs like the ones championed by outlets like Driveline can increase a pitcher’s chance of injury by 24%.

Many of the proponents of this kind of training, including Boddy, do not dispute that more velocity leads to more force, but they do argue that it does not have to be taken for granted.

“We know that pitchers who gain velocity are probably going to experience greater forces [on the elbow and shoulder],” Boddy said in a 2019 Washington Post piece by Dave Sheinin. “So you should do things that can mitigate those forces, which means mechanical changes. Which is why our own studies show no increase in force — because we do a lot of biomechanical training. … The [ASMI study] said as velocity goes up, forces go up — I agree with that. But the question is: How can we not do that? We can instruct people to not do that. It’s not a given that they have to go hand in a hand.”

In their eyes, greater velocity should be the result of more efficient use of the entire kinetic chain from a pitcher’s legs, through their core and arm, not just increasing brute force through the arm.

Driveline’s “holy grail,” according to Boddy, is not velocity itself, but “efficiency” — defined as “how much velocity you can produce per normalized unit of stress.”

To that point, not only have many of the pitchers who have trained at places like Driveline – from high school and college amateurs to big leaguers – added velocity to their fastballs, but they’ve also provided testimonials that their bodies and arms feel better after their velocity training than before.

This might indicate velocity alone may not be the sole culprit of arm pain (and potentially injuries), but perhaps velocity created from sub-optimal mechanics. Fleisig seemingly agreed with that in a 2015 interview with Grantland:

“Velocity is a factor. All things being equal, throwing 95 miles per hour is more stressful than throwing 90. But throwing 95 miles per hour with good mechanics is less stressful than throwing 90 miles per hour with bad mechanics. Throwing 95 miles per hour with proper rest is less dangerous than throwing 90 miles per hour without rest.”

Have we maxed out pitch velocity?

It seems possible, maybe even likely, that we have. But, while we may not be able to meaningfully strengthen the ligaments and tendons that serve as a physical limit, we are regularly making advancements in our understanding of optimal mechanics, training methods, and rest and recovery practices, which all could serve to better counteract the negative effects of increased velocity.

Like many human innovations and technological advancements before, these advancements have been enabled by breakthroughs in our ability to measure something and build tools to measure it at scales previously thought impossible. Today’s tools like the high-speed cameras used for pitch tracking and wearable technology for measuring athlete workloads and the forces their bodies experience might just be steps along the way toward achieving a new upper limit.

Who knows what breakthroughs are coming in the future and what we might be able to do with them? Because of that, it’s impossible to know for sure where it ends. With that view, it’s maybe not surprising that there are some leaders in the private player development world who have said they would not rule out that we could see 107 or 108 MPH in the not-too-distant future:

What do you think? Have we maxed out? Or, is there more to come?

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John is a writer for Twinkie Town and Pitcher List with an emphasis on analysis. He is a lifelong Twins fan and former college pitcher. You can follow him on Twitter @JohnFoley_21.