League-wide Batted Ball Changes
About every month, podcast mate Rob Silver pours out his undying love and affection for the Rockies Charlie Blackmon. I’m not as much of Blackmon fan but this comment got me thinking.
To play devil’s advocate:
his barrel% went up.
His exit velocity went up.
His xBA and xSLG went up.
Hard hit% went up.
K% went down.
Prior to last year, he hit 28 HRs with 105 runs in his last 161 road games.
It’s possible last year’s road stats were just noise.
— Rob Silver (@RobSilver) May 10, 2020
Blackmon definitely hit the ball harder last year but so did everyone else with MLB’s juiced ball. Even with noisy data, Rob was right and Blackmon exceeded expectations.
First, here a quick rundown of Blackmon’s stats that change and by how much.
| Stat | 2018 | 2019 | Diff |
|---|---|---|---|
| Max Exit Velo | 110.4 | 110.6 | 0.2 |
| Avg EV | 87.2 | 88.5 | 1.3 |
| Max Dist | 447 | 464 | 17 |
| Avg Dist | 173 | 189 | 16 |
| Avg LA | 11.8 | 14.5 | 2.7 |
Blackmon’s power-based measurements did see a boost up last season.
Next, the league-wide changes need to be calculated. I matched up all hitters with at least 30 batted balls in back-to-back seasons and averaged the difference.
| Season 1 | Season 2 | Max Velo | Avg Velo | Max Dist | Avg Dist | Avg HR Dist | Avg LA |
|---|---|---|---|---|---|---|---|
| 2015 | 2016 | 0.0 | 0.3 | -2.4 | -0.2 | -15.2 | 0.7 |
| 2016 | 2017 | -0.6 | -1.2 | -1.6 | 1.6 | -14.4 | 0.3 |
| 2017 | 2018 | 0.0 | 1.0 | -7.0 | -2.6 | -5.7 | 0.6 |
| 2018 | 2019 | -0.2 | 0.1 | 2.2 | 2.9 | -12.3 | 0.7 |
The preceding table is one huge data hodgepodge with values going up and down with little rhyme or reason. Just looking at 2018 to 2019 exit velocity numbers, they stayed about the same. The league-wide power boost was because the average distance traveled increasing between two to three feet. Blackmon blew past those averages. Now onto an interesting launch angle trend.
Over the four matched season pairs, the average hitter has seen their launch angle increase by over 2 degrees. Could the distance increase be caused by hitters going for more loft? I compared the 17 hitters last season who maintained their average launch angle (+/- 0.2 degrees) and their Max distance dropped by 5 feet but the average distance increased by 6.2 feet. Just more mixed results.
Going back to the original question
I can pre-write the conclusion for you ‘and that’s why my podcast colleague Rob Silver is an idiot’ – you’re welcome.
— Rob Silver (@RobSilver) May 10, 2020
Rob … I can’t call you an idiot this time. Instead, you just had me dive into one of the most messed up datasets and walked away more confused than when I started. Thanks.
Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.
*farther
I think the LA raise could be partially due to the super fun ball but also is part of a general trend the started with availability of stat cast data and was called LA revolution for a reason even if that is an overly simplified and reductionist term.
Many players made the change already but looking at the leaderboards the ideal average LA seems to around 15-16 degrees and the league still only is at 12-13 which is up a lot compared to pre statcast but also means quite a few players have not adjusted yet (or be replaced by minor leaguers who already learned that in the minors) so I assume the launch angle and swing optimization will continue until the league average is around 15-16 which is when that kind of optimisation is finished.
This was a fun article, and love to see some Jeff v Rob action. It’s a crazy/long offseason, and this fits nicely!