Statcast has unleashed a bevy of new, fascinating data for baseball fans to take in that will only get more interesting and helpful in evaluating players as time goes on. Last week, I broke down a relatively new concept to the world of baseball in spin rates, what they mean for each pitch, and which Reds pitchers have good (or bad) ones.

This week, I’m going to look at the Reds’ pitching leaders in another stat brought to us by Statcast: exit velocity.

Generally, batted ball speed is thought of in regards to hitters, especially for sluggers like Giancarlo Stanton, who has hit a ball in excess of 120 mph (!) on many occasions — including a few en route to his victory in the Home Run Derby on Monday.

But it’s also measured for pitchers. Intuitively, a pitcher should want a low exit velocity because weaker contact means more outs, right? Well…

As I dug into the data, it was clear that it was going to be difficult to determine much from exit velocity for pitchers. The data shows that a low average exit velocity doesn’t necessarily equate to success, and a high one doesn’t always indicate a poor performance.

At the top of the leaderboard — which in this case is limited to the 145 pitchers with a minimum of 150 batted balls against them — you’ll find a bunch of the top hurlers in the game this season, including Kenta Maeda (1st), Johnny Cueto (5th), Felix Hernandez (8th), Clayton Kershaw (9th), Jake Arrieta (10th), Aaron Nola (12th), and Noah Syndergaard (18th).

But at the bottom of the list, there are also a handful of baseball’s best pitchers: Aaron Sanchez (112th), Steven Matz (115th), Trevor Bauer (119th), Masahiro Tanaka (128th), Jose Fernandez (138th), and Danny Salazar (144th).

While it might seems there’s some luck involved for those at the bottom of the list, batting average on balls in play doesn’t seem to have much to do with it. For example, Nola (.331) and Syndergaard (.337) both have higher BABIPs than Fernandez (.316), while Salazar has a BABIP (.269) right in the neighborhood of guys like Kershaw (.262) and Arrieta (.259). As Bradley Woodrum of The Hardball Times pointed out last year, there isn’t much of a correlation between BABIP and batted ball speed:

These stats do so very little to predict BABIP—in part because “hard contact” can be deep fly balls, and fly balls have the worst BABIP of all non-infield-pop-ups. And typically, weak or medium contact results in ground balls, and those have a higher BABIP.

A similar story was told last year, as Fangraphs’ Craig Edwards wrote about in September. Though there are more great pitchers at the top of the list than the bottom, it’s still difficult to say with certainty that low exit velocity equals success. Edwards did an evaluation of exit velocity for pitchers, and determined a slight correlation between FIP and exit velocity that largely ties in to a pitcher’s ability to prevent home runs. This makes sense, as the average exit velocity on home runs this year is 103.4 mph. That said, home runs typically make up a small percentage of batted balls, so it’s still difficult to read into this too much.

With all of this in mind, let’s look at the Reds’ leaders in exit velocity this season:

reds exit velocities

(Feel free to take a moment to gather yourself after seeing some of the unsightly numbers.)

The only Reds pitcher with better-than-average numbers across the board is Raisel Iglesias, with Michael Lorenzen posting superior numbers in several areas, as well.

How do Edwards’ conclusions hold up here?

There seems to be some relationship between exit velocity and home run rate. Several of the pitchers giving up a lot of long balls are also allowing a lot of hard contact (Cody Reed, J.J. Hoover, Jon Moscot, Alfredo Simon), though there are some obvious outliers (hello, Keyvius Sampson and Blake Wood).

Based on the Reds’ numbers, there’s nothing all that significant to take away from ERA and ERA estimators. There are more pitchers with below average exit velocities who also have a below average ERA, xFIP, and SIERA, but not by much. And whatever correlation is there has to be taken with a grain of salt. The estimators heavily take strikeouts and walks into consideration, which have nothing to do with exit velocity off the bat. Moreover, this is a small sample size for many players, so it’s difficult to read into the data all that much.

Basically, I wrote all of that to say that there isn’t a whole lot to say about exit velocity right now. (But hey, I did all the research, so I might as well share it with you guys, right?)

At this point, it doesn’t factor into any statistic directly, making it difficult to make any real connections. Many of the best pitchers in baseball hold opposing hitters to low batted ball speeds, but others allow hard contact more frequently and still manage to get great results. There are reasons to think exit velocity matters for pitchers to some extent, but much more data is needed before we can make any definitive conclusions about what it means for pitchers and whether it’s a “repeatable skill,” as Craig Edwards put it. But Statcast has gotten the ball rolling, and we’ll learn even more in the coming years.

7 Responses

  1. streamer88

    This stat is too dirty to be of much use. Some pitchers pitch up/in to induce fly ball contact, others do not. Not all hitters are swinging for max velocity on 2 strikes, or when a runner is on 2nd or 3rd. Pitchers like Cody Reed, who induce alot of swing/misses, may have their numbers skewed by the balls actually put in play, which would be less than others. These numbers may be different by ballpark, as pitchers adjust their strategy by park size, however smart that would be. Lastly, some pitchers never alter their strategy on 2-0, 3-0 and would rather give up a BB than a sharply hit middle-in fastball.

    • streamer88

      Sorry – have more: These stats are interesting though, thanks for article. I will add they force me to contemplate the risk of observation bias we take with stats like these. I firmly believe (part of) the reason we have so many TJ issues with pitchers is due to the heavy reliance on the pitch speed odometer. Pitchers are now obsessed with velocity and as a byproduct of non-players advances (the gun) it has altered the game on the field (higher pitch speeds, injuries). Our observation in that case altered the game. I fear as we gain advanced technology with batted ball speeds it will be the batter’s turn to adjust, i.e. never “try to go the other way” or “choke up” as it will bring their numbers down.

      Ok I’m finished – thanks for reading.

  2. WVRedlegs

    Nice work, Matt. Just using your chart, creating a bullpen of Iglesias, JSmith, Lorenzen, Cingrani, Finnegan, Straily, and Wood might be a significant upgrade over the first half bullpen. Other mitigating factors are involved, so we probably won’t see a bullpen with these 7.

  3. Doug Gray

    I think that eventually we will see that exit velocity does matter some, and that pitchers can control it some (though not as much as hitters can). Much like BABIP.

    Right now, I believe we are still dealing with a few issues. First, is sample size. We’ve got less than two full seasons worth of data to look at for most pitchers in baseball. That may not be enough, though maybe it is and we just haven’t found the proper way to use the data set just yet (maybe there’s something more important within that data – such as the exit velocity on certain types of pitches: a guy has a low exit velo on his fastball, which he throws 65% of the time, but his breaking ball gets clobbered – overall the total exit velo looks fine because he throws his fastball so much more, but whenever he uses that breaking ball, it’s getting beat up and all kinds of bad is happening that is altering the overall numbers. Maybe we need to look at the exit velo on fly balls only since those are the ones that tend to go for extra-bases and lead to more runs. Just two things that maybe the overall numbers are hiding, but are of value – just spitballing ideas).

    When we start looking at relievers, these things are even more magnified because the sample size is small.

    Just like any other stat, nothing is telling the entire story. Giancarlo Stanton hits the ball harder than anyone alive, but he’s not the best hitter. Why? Because he strikes out so often that it limits the damage he can do overall.

    End of the day, assuming one believes that a pitcher can indeed control the exit velocity on their pitches somewhat, then this stat is indeed useful. How useful, well, it’s not the be-all-end-all. Strikeouts and walks are still going to be more important because they have more impact. But, if you can do all three well, it’s probably fairly telling. Hitting the ball less hard isn’t good for run production. We absolutely know this based on the results of all of the data. This chart is a little bit old at this point, but here’s what the exit velocity from 2015 showed us:

    Exit velo MLB AVG on BIP
    115-119 .780
    110-114 .726
    105-109 .689
    100-104 .561
    95-99 .397
    90-94 .276
    85-89 .227
    80-84 .221

    There’s a clear and direct correlation to how hard a ball is hit and how frequently it goes for a hit. Once you get below 80 MPH things change and you see some variations in the numbers – bunts come into play, little bleeders and bloops – but the majority of balls are hit between 80 and 100 MPH. And the harder it’s hit, the more likely it’s going for a base hit of some kind. Lower exit velo matters.

    • Doug Gray

      To note: the exit velo/AVG chart is from Daren Willman, who is now the Statcast guru for MLB Advanced Media.

    • Patrick Jeter

      Good write-up, Matt.

      I think Doug hit on some important points here, namely sample size and pitch usage.

      When you look at the buckets he provided, it accounts for all pitch types, all batted ball types, all types of hitters, etc. So with big samples, we see a very clear and direct correlation, as he states.

  4. redbonebuck

    Nice read…. In my thoughts exit velocity is directly tied to movement on each pitch. It;s much harder to drive a ball with late movement versus a smoker down the heart. Think Arroyo here, when he threw a big snapdragon that hung it was generally a moon shot.