What happens when a pitcher hits triple digits?

Perhaps nothing is more electrifying than seeing a pitcher light up the radar gun with triple digit fastballs. Back in the day Nolan Ryan was the king of the heater, and before him Bob Feller could throw a fastball past a speeding motorcycle. Steve Dalkowski, who never reached the major leagues, probably threw harder than either of them. Nowadays, Aroldis Chapman is indisputably the owner of the best fastball in baseball. This year there is a total of 102 fastballs that have reached 100 miles-per-hour, and Chapman has thrown 71 of them. Kelvin Herrera is second with 12. In the PITCHf/x era, Chapman has thrown more than twice as many 100 mph heaters as the next closest person, former Detroit Tigers flamethrower Joel Zumaya.

Quite obviously, the triple digit fastball is a very difficult pitch to hit. Of the 2029 fastballs that have registered at least 100 mph in the PITCHf/x era, hitters have swung and missed at 334 of them, for a 16.5 percent swinging strike rate. That's nearly triple the whiff rate for the average fastball. Batters swing and miss more often when the pitcher is pumping extreme heat. What else happens when the radar gun hits triple digits?

Well, seeing as this is Beyond the Box Score, what better way to reveal the results than a chart?

The sample consists of just under 300 balls in play. That's enough to have a high degree of confidence in the fly ball and ground ball rates. HR/FB rate and BABIP, however, take way more balls in play to stabilize. Color me surprised though, a lot of these numbers look like the major league average for all pitches. The distribution of ground balls, fly balls and line drives is within a few percentage points of the major league average, and so is BABIP. Not surprisingly, the HR/FB ratio is way down, due to the fact that it's very difficult to pull a 100 mph fastball. Only three hitters have hit a home run on one of these pitches. These noteworthy souls are Paul Konerko, Tyler Greene and Jose Lopez. Yeah, I'm as surprised as you are. Chapman gave up one of these shots, and Andrew Cashner surrendered the other two.

There are a few other surprising nuggets of information when it comes to the extreme heat. The swing rate is more than ten percentage points higher than the overall swing rate on fastballs. Also, the overall strike rate on triple digit fastballs is only two percentage points higher than the major league average, despite the swing rate being much higher. This of course means that triple digit fastballs are more likely to be outside the strike zone, but hitters swing anyways. Having less reaction time results in more bad decisions.

A 100 mile-per-hour fastball is a very difficult pitch to hit. However, that's mainly due to the fact that it's really tough to put into play. When hitters do put the ball between the lines it appears that they get plenty of exit velocity, as their in-play batting average is consistent with major league norms. It's almost a sure thing that a 100 mph fastball won't leave the park.

Despite the sheer awesomeness of the 100 mph fastball, it's no guarantee that it's thrower is effective. Chapman is an elite relief pitcher, and Herrera is pretty good. But, Zumaya had a career 102 xFIP-, and Henry Rodriguez checks in at 118, due to a 15.6 percent walk rate. Bruce Rondon showed some promise in 30 outings with the Detroit Tigers last season, but he was bitten by the Tommy John bug. That rounds out the top five, and no other pitcher since 2008 has thrown at least 80 pitches of at least 100 mph.

In a sense, 100 miles-per-hour is an arbitrary checkpoint; 99 mph just doesn't get people excited like triple digits do. Batters whiff way more often when pitchers turn the heat up, but other than that, the results are pretty surprisingly similar.

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Stats courtesy of Fangraphs and Baseball Savant

Chris Moran is a former college baseball player and current law student at Washington University in St. Louis. He's also an assistant baseball coach at Wash U. In addition to Beyond The Box Score, he contributes at Prospect Insider and Gammons Daily. He went to his first baseball game at age two. Follow him on Twitter @hangingslurves