As part of our discussion of the new low-scoring run environment across baseball, let’s take a look at rising fastball velocity and see what effect that may have.

Aroldis Chapman has been thrilling Reds fans with his blazing fastball ever since he burst upon the scene in 2010. We all know he set the all-time record with a 105.1 mph heater in his rookie season, but did you know he has thrown 975 pitches at 100 mph or higher? The next highest total belongs to former Tiger’s flamethrower Joel Zumaya with 310. In fact, since 2008 when PITCHf/x was installed in every ballpark, there have been 57 pitchers who reached the magical 100 mph threshold at least once. The only other Red besides Chapman to hit that mark was Jumbo Diaz, who did it once last year. Jonathan Broxton has done it 51 times but all of those came before he joined the Reds.

Most of the pitchers who can hit 100 mph are relievers, only 12 of the 57 did it as a starting pitcher. The recent trend of using relievers in short stints has allowed them to come into the game firing as hard as they can on every pitch, with no consideration for pacing themselves to last multiple innings.

In earlier eras there were always a few pitchers who stood out for their speed. Walter Johnson and Smoky Joe Wood were the famous fireballers of the Dead Ball Era. Bob Feller and Satchel Paige were the heat-bringers of the 1940’s and 50’s. Bob Gibson in the 60’s. Then along came Nolan Ryan in the 1970’s and 80’s to strike fear into hitters everywhere. Randy Johnson was the most notorious flamethrower of the 1990’s and 2000’s. But those guys were the rare exception to the rule, most pitchers in those days threw much more softly than the pitchers of today. Unfortunately we don’t have reliable velocity numbers for those years. Radar guns didn’t become common in ballparks until the late 1980’s and they were wildly inaccurate, often calibrated to yield artificially high speeds. On top of that, nobody bothered to record the results for posterity.

From radar evidence we can be fairly certain that major league fastballs averaged around 88-89 mph in the 1980’s before ticking up to 89-90 mph in the 1990’s, coinciding with increased relief pitcher specialization. The Reds and Lou Piniella were pioneers of this trend with the Nasty Boys, especially the hard-throwing Rob Dibble. Fastball velocities continued to creep up through the early 2000’s until 2008 when we started getting extremely accurate velocity data when the PITCHf/x system was installed in all 30 ballparks:

Fastball Velocity in MPH from PITCHf/x

Fastball Velocity in MPH from PITCHf/x

We can see that velocity was up to 90.8 mph in 2008 and has risen steadily since then, reaching an average of 92.1 mph last year. At first glance it might not seem that an increase of 2-4 mph over two decades would have a major effect on run scoring in the major leagues. Perhaps there is not a big difference between 90 and 92, but there is a very big difference between 86 and 94. Back when the average fastball was 89 mph there were a lot of guys throwing 85 or 86. Last year there were only 8 pitchers who averaged 86 mph or lower with their fastball. One of them was a knuckleballer (R.A. Dickey). Bronson Arroyo was another. On the flip side, there were 80 pitchers who averaged 94 mph or higher. It would be like going back to 1990 and replacing the 80 slowest pitchers with 80 flamethrowers. That is going to make a big difference across the league.

Runs/Game per Team

Runs/Game per Team

Here we can see that run scoring has dropped in inverse proportion to velocity’s rise. It makes perfect sense that harder fastballs are more difficult to hit, leading to a sharp drop in runs scored. But we know increased velocity is not the only factor that has led to a decline in scoring. As we have learned from the other articles in this series, there are many reasons why runs are down: reduced PED usage, larger strike zone, defensive shifting, increased usage of the cut fastball, heat maps that identify hitters’ weaknesses, bullpen matchups/specialization, improved surgical techniques that get injured pitchers back on the mound, the Coor’s Field humidor and several more factors.  So we need to try to separate the effect of increased fastball velocity from the other reasons why scoring is down. This should help make the correlation clearer:

Fastball Velocity in MPH vs Earned Run Average

Fastball Velocity in MPH vs Earned Run Average

As velocity goes up, ERA goes down. The harder you throw, the fewer runs you allow. This data was from the 2014 season. The first couple of data points on the left and the last couple on the right don’t quite match the trend, but that is likely because there were only one or two pitchers in each “bucket”. For example, Aroldis Chapman was the only pitcher who averaged 100 mph, so his 2.00 ERA is the only data point in the 100 mph bucket. Similarly, Mark Buehrle was the only pitcher in the 84 mph bucket. The middle section of the graph from 88-97 all have good sample sizes and allow us to see the clear trend.

Here it comes, hit it if you can.

Now we know that high velocity prevents runs. But how does this happen?…

Fastball Velocity in MPH vs Strikeout Rate in 2014

Fastball Velocity in MPH vs Strikeout Rate in 2014

… because high velocity leads to more strikeouts. The chart shows a smooth and steady increase in strikeout rate as velocity grows. Fast pitches give the batter less time to react, make a decision and put a good swing on the ball. The dip in the chart at 98 mph is due to the fact that only one pitcher averaged 98 mph (Kelvin Herrera of the Royals) and his K% was a mediocre 20%. With a larger sample in that bucket it is likely that data point would climb closer to the trend line of the rest of the graph. I didn’t want to take data from multiple seasons because velocity is not the only factor causing scoring to decline. There are other factors at work that could obscure the effect of velocity if I included data from prior seasons.

Size Matters

Now we know that velocity is a critical factor and one of the primary reasons that strikeouts are up and scoring is down across baseball. Why has velocity been steadily increasing for the last two decades? There are multiple reasons. One reason is the pitchers are simply bigger and stronger than they used to be.

Size of Pitchers

As shown by Hunter Atkins (ESPN), pitchers have gone from 6’1” 189 pounds in the 1950’s up to 6’3” 206 pounds today. Notice that pitchers are even bigger and stronger today than they were during the so-called “Steroid Era” (the hitters are too), even though half of the players suspended for PEDs or listed in the Mitchell Report were pitchers. Velocities are higher now than they were when pitchers were ‘roided up 10-15 years ago.

It just makes sense that bigger, stronger pitchers are going to throw harder – and they do. Have you ever heard the story of how the Big Red Machine superstars laughed at trainer Larry Starr when he had a Nautilus machine installed at Riverfront Stadium? They ridiculed him and refused to use it. Those of you who have taken a ballpark tour of GABP might have seen the Reds’ modern strength and conditioning facility. It is a far cry from the tiny, stuffy room with a few barbells and a bench press in the old stadium. Players today benefit from world-class fitness training to strengthen their entire bodies, not just their biceps and chest like players used to do. The players of today are remarkably stronger and in peak physical condition to max out their natural talent. The players of prior decades were not and the difference shows on the field.

Another reason that pitchers throw harder today is because of the way they are groomed as kids and teenagers. The best athletes focus only on one sport and begin intense training and competition year round at a young age. They play a lot more baseball games and receive much better coaching than they did last century. There are a lot more camps, clinics, personal pitching instructors and fitness clubs available to today’s young pitchers. Coaches have learned to avoid abusing their players’ young arms. Pitch counts and innings limits have helped prevent injuries and maximize performance. Improved coaching has led to better mechanics and the ideal delivery for maximizing velocity.

Another factor in the speed bonanza is that teams have seen the data showing how important pure velocity is, so they have placed more emphasis on it when scouting, drafting and developing young pitchers. Remember former Reds’ General Manager Dan O’Brien and his infamous “pitch to contact” mantra? Yeah, well teams don’t do that anymore. They have realized that the best way to get outs as a pitcher is to strike the batters out. Velocity used to play second fiddle to control and a varied repertoire. That is no longer the case. Teams place a higher priority on raw speed and power than they used to.

Building Muscle Does Not Strengthen The UCL

But the increased focus on velocity has a downside too. Throwing 95 to 100 mph puts tremendous strain on the elbow. The harder you throw the more likely you are to rupture a ligament in your elbow. The epidemic of Tommy John surgery can be blamed squarely on the elbow torque from the extreme fastball speed and throwing hard breaking balls like the cutter.

The good news is that modern surgical techniques can repair the elbow and get the pitcher back on the mound quickly. Recent studies have shown that about 95% of pitchers have returned to the mound after TJ surgery. 80-85% return at full effectiveness and some are even better after TJS. This is another reason why velocity is up, because the best pitchers can get hurt and later return to full effectiveness. In prior decades if a top pitcher blew out his arm or shoulder he would either try to continue to pitch at a much lower level of effectiveness or his career would be ended and he would be replaced by another, presumably less effective, pitcher.

The improved handling of young pitchers in terms of coaching, fitness and reduced abuse of tender arms has resulted in a larger number of good young pitchers “surviving” through their high school and minor league years to pitch in the major leagues. Pitchers who in yesteryear would have blown out their arms at a young age, never to be heard from again are now making it to the major leagues before suffering their arm injuries. In effect, fewer injuries to young pitchers have led to more injuries to major league pitchers. That means teams are getting at least some major league time out of their draftees before they blow out their arms, which can then be repaired by the big-budgeted major league franchises and their affiliated surgeons. It all has the effect of keeping the most talented arms on the mound in the major leagues for longer periods of time, negating the need to permanently replace them with lesser talent.


Pitchers today are throwing harder than ever before. 95 mph fastballs used to be rare and unique, but today every team in baseball has multiple pitchers who can deal that type of heat. That extreme velocity has led to record-breaking strikeout rates and reduced scoring throughout the major leagues. The reasons why pitch speeds have increased are because the players are bigger and stronger with better mechanics. If they get hurt the doctors can repair them and get them back on the mound again. It is a great time to be a pitcher!