Using StatCast and BIS Batted Ball Data to Assess Expected Power Output
Major League front offices have had access to comprehensive StatCast data all season, data that describes essentially everything quantifiable about the movements of fielders, baserunners, batters and the baseball. Those of us in the public realm have only been privy to what’s released sparsely through MLB’s GameDay and At Bat applications. Baseball Savant, an invaluable resource for many things created by Daren Willman, has collected exit velocity and distance for most at bats, presenting it in the form of aggregate statistics for individual players. The data seems to be a little messy, as Jeff Sullivan found, but there’s enough of it that anomalies should be smoothed over enough to make critical conclusions.
At the same time, Baseball Info Solutions has been collecting data for contact quality and direction for every plate appearance since 2002, using manual data entry. Fangraphs recently shared this data on their site, providing information that should prove very useful in lieu of more detailed StatCast or Hitf/x outputs.
This article is my first foray into the new batted ball information and will present a fairly basic expression of expected isolated power. I looked at all hitters in 2015 with at least 65 at-bats of StatCast data and 100 plate appearances overall (all statistics through June 7th) and merged the datasets together to derive an appropriate regression. The good thing about isolated power is that it isn’t that dependent on things such as speed that are immeasurable with by this data. If I were to create a similar metric in the future to predict BABIP or more general measures of production, more datasets would need to be included to capture the additional significant player effects.
The model I came up with uses main effects for average fly ball velocity, average ground ball velocity, average distance, hard-hit percentage and pull percentage, and the interaction effects between average fly ball velocity and average feet, and average fly ball velocity and average ground ball velocity. Basically, it includes effects for each distinct element of contact quality. All together, we have a fair amount of quality data here, but as the season continues the model will need to be re-tuned to account for the new information.
This chart shows a pretty tight fit. If you hit the ball hard, at the right angle and in the right direction, you’re liable to hit a lot for many extra bases. Some players stick out on the chart and I’ve highlighted them with labels. Bryce Harper has hit the ball very hard this year and has been rewarded. But he appears to be hitting above his means and doesn’t deserve to be running away with the sport’s ISO lead. Fifteen hitters have posted better expected isolated slugging percentages.
Taking this information at face value (as a legitimate metric that measures more talent and less noise than standard ISO), we could say that these players can be expected to perform closer to if not at their expected marks in the future. Players who have outperformed their expected isolated power have been lucky to generate so many extra bases given their contact quality, while players who have underperformed have been unlucky. Here is the full table, for reference.
Name | xISO | ISO | Spread |
---|---|---|---|
Giancarlo Stanton | 0.315 | 0.3 | -0.015 |
Joc Pederson | 0.311 | 0.32 | 0.009 |
Steven Souza | 0.293 | 0.22 | -0.073 |
Chris Davis | 0.282 | 0.25 | -0.032 |
Brandon Moss | 0.268 | 0.234 | -0.034 |
Todd Frazier | 0.267 | 0.311 | 0.044 |
Paul Goldschmidt | 0.26 | 0.313 | 0.053 |
Brandon Belt | 0.257 | 0.215 | -0.042 |
Ryan Howard | 0.256 | 0.25 | -0.006 |
Pedro Alvarez | 0.244 | 0.209 | -0.035 |
Freddie Freeman | 0.243 | 0.221 | -0.022 |
Troy Tulowitzki | 0.24 | 0.191 | -0.049 |
Mark Teixeira | 0.236 | 0.328 | 0.092 |
Jay Bruce | 0.235 | 0.196 | -0.039 |
Chris Carter | 0.234 | 0.187 | -0.047 |
Bryce Harper | 0.23 | 0.38 | 0.15 |
Ryan Braun | 0.227 | 0.242 | 0.015 |
J.D. Martinez | 0.227 | 0.194 | -0.033 |
Mike Trout | 0.226 | 0.278 | 0.052 |
Adrian Gonzalez | 0.225 | 0.266 | 0.041 |
Mark Trumbo | 0.225 | 0.226 | 0.001 |
Adam Lind | 0.223 | 0.219 | -0.004 |
Colby Rasmus | 0.223 | 0.242 | 0.019 |
Alex Rodriguez | 0.219 | 0.242 | 0.023 |
Mike Napoli | 0.219 | 0.196 | -0.023 |
Brian Dozier | 0.218 | 0.263 | 0.045 |
Starling Marte | 0.218 | 0.217 | -0.001 |
Andrew McCutchen | 0.215 | 0.208 | -0.007 |
Evan Gattis | 0.215 | 0.244 | 0.029 |
Anthony Rizzo | 0.214 | 0.276 | 0.062 |
Adam LaRoche | 0.213 | 0.161 | -0.052 |
Josh Donaldson | 0.213 | 0.264 | 0.051 |
Khris Davis | 0.212 | 0.196 | -0.016 |
Miguel Cabrera | 0.211 | 0.238 | 0.027 |
Curtis Granderson | 0.211 | 0.156 | -0.055 |
Lucas Duda | 0.209 | 0.22 | 0.011 |
Luis Valbuena | 0.208 | 0.214 | 0.006 |
Nelson Cruz | 0.206 | 0.284 | 0.078 |
Brett Lawrie | 0.204 | 0.126 | -0.078 |
Jose Bautista | 0.204 | 0.279 | 0.075 |
Mitch Moreland | 0.204 | 0.204 | 0 |
Shin-Soo Choo | 0.204 | 0.186 | -0.018 |
David Freese | 0.203 | 0.191 | -0.012 |
Steve Pearce | 0.201 | 0.15 | -0.051 |
Danny Espinosa | 0.201 | 0.203 | 0.002 |
Yoenis Cespedes | 0.2 | 0.2 | 0 |
Devon Travis | 0.199 | 0.233 | 0.034 |
Nolan Arenado | 0.199 | 0.272 | 0.073 |
Charlie Blackmon | 0.199 | 0.158 | -0.041 |
Evan Longoria | 0.196 | 0.141 | -0.055 |
Brandon Crawford | 0.195 | 0.203 | 0.008 |
David Peralta | 0.195 | 0.207 | 0.012 |
Joey Votto | 0.194 | 0.225 | 0.031 |
Brad Miller | 0.192 | 0.179 | -0.013 |
Jason Castro | 0.191 | 0.176 | -0.015 |
Jorge Soler | 0.19 | 0.138 | -0.052 |
Jose Abreu | 0.188 | 0.199 | 0.011 |
Marlon Byrd | 0.187 | 0.23 | 0.043 |
Eric Hosmer | 0.187 | 0.188 | 0.001 |
George Springer | 0.186 | 0.182 | -0.004 |
Carlos Santana | 0.186 | 0.155 | -0.031 |
Gerardo Parra | 0.184 | 0.157 | -0.027 |
Edwin Encarnacion | 0.184 | 0.219 | 0.035 |
Matt Adams | 0.183 | 0.132 | -0.051 |
Andre Ethier | 0.182 | 0.212 | 0.03 |
Will Middlebrooks | 0.181 | 0.178 | -0.003 |
Prince Fielder | 0.181 | 0.191 | 0.01 |
Albert Pujols | 0.18 | 0.249 | 0.069 |
Michael Cuddyer | 0.18 | 0.141 | -0.039 |
Michael Morse | 0.18 | 0.078 | -0.102 |
Yasmani Grandal | 0.179 | 0.16 | -0.019 |
Marcell Ozuna | 0.178 | 0.101 | -0.077 |
Marwin Gonzalez | 0.176 | 0.126 | -0.05 |
Logan Forsythe | 0.175 | 0.184 | 0.009 |
Jhonny Peralta | 0.174 | 0.203 | 0.029 |
Stephen Vogt | 0.173 | 0.254 | 0.081 |
Chris Coghlan | 0.173 | 0.194 | 0.021 |
Jimmy Paredes | 0.171 | 0.179 | 0.008 |
Matt Carpenter | 0.171 | 0.223 | 0.052 |
Adam Jones | 0.171 | 0.198 | 0.027 |
Josh Reddick | 0.17 | 0.205 | 0.035 |
Brian McCann | 0.17 | 0.218 | 0.048 |
A.J. Pierzynski | 0.169 | 0.152 | -0.017 |
David Ortiz | 0.169 | 0.156 | -0.013 |
Miguel Montero | 0.168 | 0.172 | 0.004 |
Kris Bryant | 0.167 | 0.19 | 0.023 |
Seth Smith | 0.165 | 0.226 | 0.061 |
Wil Myers | 0.164 | 0.201 | 0.037 |
Christian Yelich | 0.164 | 0.063 | -0.101 |
Neil Walker | 0.164 | 0.132 | -0.032 |
Justin Turner | 0.163 | 0.189 | 0.026 |
Carlos Beltran | 0.163 | 0.153 | -0.01 |
Marcus Semien | 0.163 | 0.149 | -0.014 |
Logan Morrison | 0.162 | 0.131 | -0.031 |
David DeJesus | 0.162 | 0.16 | -0.002 |
Lorenzo Cain | 0.162 | 0.126 | -0.036 |
Billy Butler | 0.161 | 0.1 | -0.061 |
Eduardo Escobar | 0.161 | 0.125 | -0.036 |
Kendrys Morales | 0.16 | 0.176 | 0.016 |
Torii Hunter | 0.16 | 0.171 | 0.011 |
Carlos Gomez | 0.158 | 0.179 | 0.021 |
Nick Castellanos | 0.157 | 0.122 | -0.035 |
Carlos Gonzalez | 0.156 | 0.137 | -0.019 |
Ian Desmond | 0.155 | 0.141 | -0.014 |
Kyle Seager | 0.155 | 0.184 | 0.029 |
Matt Duffy | 0.155 | 0.134 | -0.021 |
Mark Canha | 0.155 | 0.184 | 0.029 |
Hanley Ramirez | 0.154 | 0.214 | 0.06 |
Chase Headley | 0.154 | 0.133 | -0.021 |
Chris Colabello | 0.154 | 0.174 | 0.02 |
Derek Norris | 0.153 | 0.181 | 0.028 |
Yangervis Solarte | 0.153 | 0.104 | -0.049 |
Robinson Cano | 0.152 | 0.081 | -0.071 |
Justin Upton | 0.152 | 0.215 | 0.063 |
Adrian Beltre | 0.15 | 0.15 | 0 |
Buster Posey | 0.15 | 0.165 | 0.015 |
Salvador Perez | 0.15 | 0.176 | 0.026 |
Caleb Joseph | 0.149 | 0.138 | -0.011 |
A.J. Pollock | 0.149 | 0.173 | 0.024 |
Russell Martin | 0.149 | 0.215 | 0.066 |
Trevor Plouffe | 0.149 | 0.184 | 0.035 |
Dustin Ackley | 0.148 | 0.134 | -0.014 |
Alex Gordon | 0.147 | 0.175 | 0.028 |
Wilmer Flores | 0.147 | 0.175 | 0.028 |
David Murphy | 0.145 | 0.147 | 0.002 |
Avisail Garcia | 0.145 | 0.141 | -0.004 |
Jordy Mercer | 0.145 | 0.073 | -0.072 |
Kolten Wong | 0.145 | 0.156 | 0.011 |
Matt Kemp | 0.144 | 0.097 | -0.047 |
Dustin Pedroia | 0.143 | 0.148 | 0.005 |
Nick Hundley | 0.143 | 0.166 | 0.023 |
Daniel Murphy | 0.142 | 0.131 | -0.011 |
Mookie Betts | 0.141 | 0.133 | -0.008 |
Ryan Zimmerman | 0.14 | 0.14 | 0 |
Kevin Kiermaier | 0.139 | 0.175 | 0.036 |
Conor Gillaspie | 0.138 | 0.127 | -0.011 |
Manny Machado | 0.137 | 0.187 | 0.05 |
Francisco Cervelli | 0.137 | 0.074 | -0.063 |
Starlin Castro | 0.135 | 0.087 | -0.048 |
Zack Cozart | 0.135 | 0.174 | 0.039 |
Kevin Pillar | 0.133 | 0.122 | -0.011 |
Jake Marisnick | 0.133 | 0.148 | 0.015 |
Austin Jackson | 0.132 | 0.114 | -0.018 |
Cody Asche | 0.13 | 0.094 | -0.036 |
Asdrubal Cabrera | 0.13 | 0.104 | -0.026 |
Kole Calhoun | 0.13 | 0.123 | -0.007 |
Yasmany Tomas | 0.129 | 0.085 | -0.044 |
Alexei Ramirez | 0.129 | 0.087 | -0.042 |
Yadier Molina | 0.128 | 0.048 | -0.08 |
Victor Martinez | 0.128 | 0.054 | -0.074 |
Ike Davis | 0.126 | 0.146 | 0.02 |
Josh Harrison | 0.126 | 0.132 | 0.006 |
Michael Brantley | 0.126 | 0.159 | 0.033 |
Odubel Herrera | 0.126 | 0.117 | -0.009 |
Jeff Francoeur | 0.125 | 0.169 | 0.044 |
Aramis Ramirez | 0.124 | 0.166 | 0.042 |
Brett Gardner | 0.123 | 0.16 | 0.037 |
Will Venable | 0.122 | 0.148 | 0.026 |
Jimmy Rollins | 0.122 | 0.135 | 0.013 |
Joe Panik | 0.122 | 0.141 | 0.019 |
Martin Prado | 0.12 | 0.087 | -0.033 |
Juan Uribe | 0.12 | 0.112 | -0.008 |
Rene Rivera | 0.12 | 0.08 | -0.04 |
Cory Spangenberg | 0.119 | 0.113 | -0.006 |
J.T. Realmuto | 0.118 | 0.135 | 0.017 |
Kurt Suzuki | 0.117 | 0.079 | -0.038 |
Mike Moustakas | 0.117 | 0.146 | 0.029 |
Ender Inciarte | 0.115 | 0.093 | -0.022 |
Delmon Young | 0.115 | 0.077 | -0.038 |
Gregory Polanco | 0.115 | 0.109 | -0.006 |
Brock Holt | 0.114 | 0.116 | 0.002 |
Lonnie Chisenhall | 0.113 | 0.136 | 0.023 |
Jason Kipnis | 0.113 | 0.18 | 0.067 |
Ryan Goins | 0.113 | 0.09 | -0.023 |
Nick Ahmed | 0.113 | 0.099 | -0.014 |
Jason Heyward | 0.113 | 0.132 | 0.019 |
Denard Span | 0.113 | 0.165 | 0.052 |
Jose Altuve | 0.112 | 0.107 | -0.005 |
DJ LeMahieu | 0.112 | 0.094 | -0.018 |
Johnny Giavotella | 0.112 | 0.092 | -0.02 |
Matt Joyce | 0.111 | 0.138 | 0.027 |
Nick Markakis | 0.111 | 0.067 | -0.044 |
Pablo Sandoval | 0.111 | 0.111 | 0 |
Leonys Martin | 0.111 | 0.102 | -0.009 |
Andrelton Simmons | 0.11 | 0.117 | 0.007 |
Xander Bogaerts | 0.109 | 0.106 | -0.003 |
Jean Segura | 0.108 | 0.127 | 0.019 |
Adeiny Hechavarria | 0.108 | 0.121 | 0.013 |
Howie Kendrick | 0.108 | 0.144 | 0.036 |
Joe Mauer | 0.107 | 0.101 | -0.006 |
Dexter Fowler | 0.107 | 0.15 | 0.043 |
Stephen Drew | 0.107 | 0.168 | 0.061 |
Cameron Maybin | 0.106 | 0.132 | 0.026 |
Adam Eaton | 0.106 | 0.129 | 0.023 |
Brandon Phillips | 0.106 | 0.079 | -0.027 |
Chase Utley | 0.105 | 0.119 | 0.014 |
James McCann | 0.105 | 0.126 | 0.021 |
Michael Bourn | 0.104 | 0.058 | -0.046 |
Jose Reyes | 0.103 | 0.087 | -0.016 |
Elvis Andrus | 0.102 | 0.079 | -0.023 |
Erick Aybar | 0.099 | 0.052 | -0.047 |
Juan Lagares | 0.099 | 0.071 | -0.028 |
Jace Peterson | 0.099 | 0.074 | -0.025 |
Melky Cabrera | 0.098 | 0.032 | -0.066 |
Danny Santana | 0.095 | 0.073 | -0.022 |
Jose Ramirez | 0.093 | 0.06 | -0.033 |
Wilson Ramos | 0.093 | 0.117 | 0.024 |
Chris Owings | 0.092 | 0.089 | -0.003 |
Matt Holliday | 0.092 | 0.113 | 0.021 |
Sam Fuld | 0.092 | 0.096 | 0.004 |
Ian Kinsler | 0.089 | 0.089 | 0 |
Jon Jay | 0.089 | 0.016 | -0.073 |
Yunel Escobar | 0.089 | 0.072 | -0.017 |
Omar Infante | 0.088 | 0.087 | -0.001 |
Brandon Guyer | 0.087 | 0.107 | 0.02 |
Jacoby Ellsbury | 0.084 | 0.047 | -0.037 |
Anthony Gose | 0.083 | 0.11 | 0.027 |
Didi Gregorius | 0.08 | 0.073 | -0.007 |
James Loney | 0.077 | 0.101 | 0.024 |
Eric Sogard | 0.076 | 0.039 | -0.037 |
Alcides Escobar | 0.074 | 0.091 | 0.017 |
Dee Gordon | 0.074 | 0.068 | -0.006 |
Brayan Pena | 0.073 | 0.053 | -0.02 |
Nori Aoki | 0.07 | 0.084 | 0.014 |
Alexi Amarista | 0.068 | 0.074 | 0.006 |
Angel Pagan | 0.067 | 0.069 | 0.002 |
Freddy Galvis | 0.065 | 0.041 | -0.024 |
Billy Hamilton | 0.06 | 0.088 | 0.028 |
Ben Revere | 0.059 | 0.083 | 0.024 |
Carlos Ruiz | 0.057 | 0.043 | -0.014 |
Alberto Callaspo | 0.055 | 0.039 | -0.016 |
Jose Iglesias | 0.053 | 0.081 | 0.028 |
Billy Burns | 0.051 | 0.117 | 0.066 |
Ichiro Suzuki | 0.007 | 0.041 | 0.034 |
The top five luckiest hitters by a straight spread are Bryce Harper, Mark Teixeira, Stephen Vogt, Nelson Cruz and Jose Bautista. They’re lucky but not bad: the average ISO of hitters in the sample is .152 while the average expected ISO of these five is .210. They’re still crushing the ball. Billy Burns, Russell Martin and Jason Kipnis populated the back spots of the top ten luckiest hitters and have below-average expected ISOs. They are players whose power production warrants concern going forward.
On the other side of the coin, two Marlins in Michael Morse and Christian Yelich are the only players to under-perform by over a tenth, while Marcell Ozuna has been the fifth most notable under-performer. A cursory glance doesn’t reveal any obvious patterns above over-performers or under-performers, and the Q-Q plot for the regression was normal.
Using new batted ball data to investigate expected peripherals seems like a worthy endeavour, something that Breaking Blue may explore further in future posts. An interesting idea would be to come up with expected measures for each fundamental peripheral (BABIP, ISO, K%, BB%) in order to produce an expected slash-line or composite stat such as wOBA.
(Title photo credit to Keith Allison, https://www.flickr.com/photos/keithallison/)
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