First-Half Exit-Velocity Overachievers and Underachievers

When a player puts up a great first half that departs considerably from his established levels, it’s generally expected that the player will come back to earth in the second half. This is regression in its simplest form, and it’s baked into the sort of projections which appear at this site. This isn’t to say the player won’t continue to be good, just that he might not be as good as he showed in the first half. The same is true for players with uncharacteristically poor first halves. We expect them to figure things out and get back closer to their prior performance level. We can look at many indicators of the poor performance — BABIP is usually prominent — and tie some of the performance to bad luck. Sometimes it’s injuries. Another avenue we can travel down is to look at exit velocity.

Over the winter, I looked at players who under- or overperformed their average exit velocities in the first half of 2015 and then compared it to their second-half production. Standard caveats about the importance of launch angle and somewhat incomplete data apply, but those players who most outperformed their exit velocity in the first half last season saw massive drops in production in the second half. Here’s the methodology I applied in February (and repeated a few weeks ago in looking at players who underperformed last season):

I created IQ-type scores for exit velocity and wOBA from the first half of last season based on the averages of the 130 players in the sample. In each case, I assigned a figure of 100 to the sample’s average and then, for each standard deviation (SD) up or down, added or subtracted 15 points.

Once the IQ scores for both stats were calculated, I subtracted the IQ score for exit velocity from the IQ score for wOBA to find the players with the biggest disparities.

Here are the overperformers from the first half of last season — i.e. the players whose production most exceeded their exit velocity:

First-Half Exit-Velocity Overperformers, 2015
2015 1st Half wOBA 2015 2nd Half wOBA Diff
Bryce Harper 0.482 0.438 -0.044
Anthony Rizzo 0.407 0.356 -0.051
Starling Marte 0.337 0.337 0
Charlie Blackmon 0.356 0.331 -0.025
Brian Dozier 0.357 0.280 -0.077
Brett Gardner 0.373 0.271 -0.102
Adrian Gonzalez 0.371 0.333 -0.038
Buster Posey 0.377 0.346 -0.031
Jhonny Peralta 0.355 0.277 -0.078
Victor Martinez 0.313 0.262 -0.051
AVERAGE 0.373 0.323 -0.050

As you can see, players who outperformed their exit-velocity numbers in the first half of 2015 produced a collective wOBA that was 50 points lower in the second half of that season.

With that in mind, here are the overperformers from the first half of this season:

First-Half Exit-Velocity Overperformers, 2016
wOBA wOBA IQ Exit Velo 1st Half 2016 Exit Velo IQ wOBA IQ-Exit Velo IQ
Brandon Belt .394 124.0 86.2 79.4 44.5
Derek Dietrich .365 113.1 86.2 79.1 34.0
Jose Altuve .400 126.2 88.7 94.5 31.7
Anthony Rizzo .419 133.3 90.3 104.5 28.9
John Jaso .327 98.9 85.0 72.1 26.8
Cameron Maybin .359 110.9 87.1 84.9 26.0
Ian Kinsler .358 110.5 87.3 85.9 24.6
Mike Trout .415 131.8 90.8 107.5 24.3
Jose Iglesias .281 81.6 82.7 58.0 23.7
Daniel Murphy .410 130.0 90.7 106.6 23.4
Didi Gregorius .339 103.4 86.4 80.2 23.1
Charlie Blackmon .371 115.4 88.4 92.6 22.8
Dexter Fowler .381 119.1 89.0 96.5 22.6
Lonnie Chisenhall .348 106.7 87.0 84.4 22.4
Stephen Piscotty .366 113.5 88.2 91.6 21.9
Matt Carpenter .414 131.5 91.3 110.6 20.8
Starling Marte .353 108.6 87.7 88.4 20.2
AVERAGE .371 115.2 87.8 89.2 26.0

On the whole, this group had a very good first half of 2016. You might notice that three names carry over from the previous season. Last, year Starling Marte increased his exit velocity in the second half and maintained his production. Anthony Rizzo’s production fell, meanwhile, but remained at a high level, and Charle Blackmon saw his numbers fall a bit. Many of these players are bound to experience a decline in production in the second half just because the numbers are high. The chart below shows the above players along with their first half wOBA — as well as their projected wOBA for the rest of the season.

First-Half Exit-Velocity Overperformers, ROS Projections
1st Half wOBA ROS Proj wOBA Difference
Brandon Belt .394 .355 .039
Derek Dietrich .365 .323 .042
Jose Altuve .400 .358 .042
Anthony Rizzo .419 .384 .035
John Jaso .327 .327 .000
Cameron Maybin .359 .317 .042
Ian Kinsler .358 .326 .032
Mike Trout .415 .414 .001
Jose Iglesias .281 .296 -.015
Daniel Murphy .410 .353 .057
Didi Gregorius .339 .309 .030
Charlie Blackmon .371 .339 .032
Dexter Fowler .381 .339 .042
Lonnie Chisenhall .348 .320 .028
Stephen Piscotty .366 .332 .034
Matt Carpenter .414 .364 .050
Starling Marte .353 .345 .008
AVERAGE .371 .341 .030

A 30-point decrease in wOBA is already expected from these players because their performances were uncharacteristically strong. Starling Marte, Mike Trout, John Jaso, and Jose Iglesias are projected to have minimal changes, while the rest of the group is expected to experience more substantial drops. Last season, a similar group dropped 50 points on average, so it will be interesting to see how this group fares the rest of the season. The easiest way to outperform your exit velocity is to draw a lot of walks; those have little to do with exit velocity but are very important to wOBA. Many of the players above are quite good at drawing walks, but that was true of last year’s group, as well, and they still experienced a drop.

Next we can turn to the group of players underperforming their exit velocity. This group of players is hitting the ball harder than would be expected given their production. This is the group from last season:

First-Half Exit-Velocity Underperformers, 2015
1st Half wOBA 2nd Half wOBA Diff
Michael Taylor 0.286 0.263 -0.023
Ryan Braun 0.356 0.381 0.025
Gregory Polanco 0.285 0.324 0.039
Christian Yelich 0.317 0.374 0.057
Yoenis Cespedes 0.349 0.389 0.040
Ian Desmond 0.258 0.337 0.079
David Ortiz 0.323 0.448 0.125
Robinson Cano 0.287 0.395 0.108
Mark Trumbo 0.307 0.351 0.044
Wilson Ramos 0.290 0.233 -0.057
AVERAGE 0.306 0.350 0.044

The members of this group experienced a 44-point increase in wOBA during the second half of 2015.

Now here are the candidates this season:

First-Half Exit-Velocity Underperformers, 2016
wOBA wOBA IQ Exit Velo 1st Half 2016 Exit Velo IQ wOBA IQ-Exit Velo IQ
Avisail Garcia .281 81.6 89.9 101.8 -20.1
Mitch Moreland .300 88.8 91.2 109.6 -20.9
Juan Uribe .273 78.7 89.5 99.6 -21.0
Kendrys Morales .332 100.7 93.2 121.9 -21.2
Yasiel Puig .308 91.8 91.8 113.2 -21.4
Adonis Garcia .275 79.4 89.8 101.1 -21.7
Anthony Rendon .326 98.5 93.0 120.7 -22.2
Yasmany Tomas .314 94.0 92.3 116.3 -22.3
Justin Smoak .318 95.5 92.7 119.2 -23.7
Brad Miller .316 94.8 92.8 119.5 -24.7
Randal Grichuk .305 90.6 92.2 115.9 -25.2
Adeiny Hechavarria .258 73.0 89.4 98.7 -25.7
Trevor Plouffe .292 85.8 91.5 111.6 -25.8
Logan Morrison .301 89.1 92.1 115.3 -26.2
Nick Markakis .302 89.5 92.2 116.2 -26.7
Chris Coghlan .232 63.3 88.1 90.6 -27.3
Justin Upton .288 84.3 91.6 112.0 -27.8
Aaron Hicks .246 68.5 89.4 98.6 -30.0
Alex Rodriguez .274 79.0 91.3 110.3 -31.3
Yan Gomes .221 59.2 88.0 90.5 -31.3
Adam Lind .292 85.8 92.6 118.4 -32.6
Giancarlo Stanton .348 106.7 96.1 139.8 -33.0
Matt Holliday .328 99.3 95.5 135.9 -36.7
Ryan Zimmerman .293 86.1 94.4 129.1 -43.0
Ryan Howard .240 66.3 92.8 119.5 -53.2
AVERAGE .291 85.2 91.7 113.0 -27.8

Just like with the overperformers, there are ways to understandably underperform. If a player strikes out a ton, then he’s limiting the number of times the decent exit velocity will work for him. One thing to note among these players is that there are no players carried over from the previous season. Every player on this list is new.

Another thing you might notice is that the list this year is considerably larger than last year’s. There’s a survival bias involved in last year’s group, as only players who played enough in both halves were examined. Some who might have made this list a year ago might have dropped off due to a lack of playing time perhaps because of their struggles. It will be interesting to see how that works this year, and we can already see with Yan Gomes and Juan Uribe that there are players who will not provide a good analysis at the end of the year because they will not have played.

As for some of the rebound being built into the projections, we have that with the underperformers as well.

First-Half Exit-Velocity Underperformers, ROS Projections
1st Half wOBA ROS Proj wOBA Difference
Avisail Garcia .281 .302 -.021
Mitch Moreland .300 .327 -.027
Juan Uribe .273 .295 -.022
Kendrys Morales .332 .331 .001
Yasiel Puig .308 .347 -.039
Adonis Garcia .275 .297 -.022
Anthony Rendon .326 .340 -.014
Yasmany Tomas .314 .316 -.002
Justin Smoak .318 .316 .002
Brad Miller .316 .317 -.001
Randal Grichuk .305 .313 -.008
Adeiny Hechavarria .258 .282 -.024
Trevor Plouffe .292 .315 -.023
Logan Morrison .301 .306 -.005
Nick Markakis .302 .311 -.009
Chris Coghlan .232 .293 -.061
Justin Upton .288 .340 -.052
Aaron Hicks .246 .295 -.049
Alex Rodriguez .274 .317 -.043
Yan Gomes .221 .287 -.066
Adam Lind .292 .316 -.024
Giancarlo Stanton .348 .379 -.031
Matt Holliday .328 .342 -.014
Ryan Zimmerman .293 .320 -.027
Ryan Howard .240 .291 -.051
AVERAGE .291 .316 -.025

Justin Upton can’t possibly be this bad over the course of a full season. Yasiel Puig and Randal Grichuk were both just sent to the minors, so it remains to be seen whether they will get an opportunity to improve their numbers. The projections for many of these players look to be closer to their first-half production, so whether or not these players improve significantly will provide evidence on whether this type of analysis is worthwhile. We’re still scratching the surface of what we should eventually be able to do with exit velocity, but the players in this post should be watched over the course of the second half to see where the production leads.





Craig Edwards can be found on twitter @craigjedwards.

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Pwn Shop
5 years ago

You changed your Positive/Negative perspective between the 2015 study and the projection study, which made my brain very hot. Otherwise interesting piece!