Spring Training Groundball Changers

Blah, blah, some intro stuff on some guy that goes on too long. And here are the hitters who might be changing their launch angle (i.e. groundball rate).

Using Spring Training Ground Outs divided by Airball Outs (GO/AO), some possible swing plane changes might already be detectable. To find possible change, I found the hitters who had a combined 50% GB% and at least 300 PA from 2019 to 2020. Then, I removed those with fewer than 30 spring plate appearances and got the GO/AO values for the rest. Next, I converted the GO/AO to groundball rate (GB%) using the formula in this article. Finally, I just calculated the greatest differences and here are the results.

Groundball Rate Changes for High Groundball Hitters
Name PA GB% LA HR/FB StatCast HardHit% maxEV PA GO/AO ST GB% Diff
Alex Verdugo 598 50% 7.9 14% 37% 111.3 30 0.50 30% -20%
Jose Iglesias 680 50% 7.2 11% 26% 110.2 35 0.57 33% -17%
Jonathan Villar 921 51% 6.6 15% 37% 114.0 31 0.71 37% -14%
Jose Altuve 758 50% 9.6 20% 34% 109.3 44 0.69 37% -13%
Vladimir Guerrero Jr. 757 51% 6 14% 43% 118.9 33 0.83 40% -11%
Yandy Diaz 485 55% 1.9 18% 41% 114.3 30 1.13 46% -9%
Isiah Kiner-Falefa 450 57% 3.6 4% 32% 106.2 36 1.29 49% -8%
Starling Marte 836 51% 7.7 17% 35% 111.6 35 1.00 44% -7%
David Peralta 641 50% 6.4 13% 39% 113.8 38 1.00 44% -6%
Steven Duggar 317 50% 8.7 7% 32% 106.8 34 1.00 44% -6%
Nicky Lopez 594 60% 2.5 3% 22% 105.4 38 1.67 54% -6%
Josh Naylor 383 53% 5.5 12% 36% 115.1 33 1.22 48% -5%
Garrett Cooper 554 51% 5.6 24% 40% 113.5 30 1.14 47% -4%
Javier Baez 796 50% 8.4 22% 42% 116.0 37 1.14 47% -4%
Wilson Ramos 679 60% 1.4 17% 42% 111.0 30 2.00 58% -3%
Luis Rengifo 512 50% 8.3 8% 30% 108.6 30 1.20 48% -2%
Dee Gordon 503 52% 7.1 3% 16% 102.5 33 1.43 51% -1%
David Bote 501 50% 8.2 21% 41% 113.8 36 1.33 50% 0%
Tommy Pham 779 55% 4.7 19% 46% 113.3 43 1.83 56% 1%
Elvis Andrus 759 51% 7.5 9% 35% 110.2 34 1.63 54% 3%
DJ LeMahieu 871 52% 5.5 21% 48% 111.1 39 1.71 55% 3%
J.D. Davis 682 50% 8.1 22% 47% 114.7 34 1.60 53% 3%
Leury Garcia 681 54% 6.3 9% 29% 108.5 41 2.17 59% 5%
Tim Anderson 739 50% 8.1 19% 37% 108.8 44 1.89 57% 6%
Orlando Arcia 735 50% 7.4 12% 33% 109.9 35 2.00 58% 8%
Ryan McMahon 732 51% 8.9 26% 47% 112.9 44 2.14 59% 8%
Jean Segura 835 51% 8.1 10% 34% 113.1 30 2.20 60% 9%
Raimel Tapia 653 53% 5.7 9% 31% 107.2 40 2.60 63% 10%
Harold Castro 423 52% 8.9 7% 30% 105.0 31 2.50 62% 10%
Eric Hosmer 823 54% 3.4 21% 46% 114.3 30 3.50 69% 15%
Erik Gonzalez 349 51% 5.1 6% 37% 112.8 32 4.00 71% 20%
Nick Solak 368 50% 8.4 9% 38% 111.7 38 5.00 76% 25%

First and most importantly, the sample size is insanely small, so this list shouldn’t factor into major ranking changes. Instead, it’s more of a factor to break ties.

Second, some hitters shouldn’t be trying to air it out. Take Isiah Kiner-Falefa for example. He just has a 4% HR/FB so most of his flyballs will be outs. From the table, here are some interesting players.

  • Alex Verdugo: A little more loft wouldn’t hurt.
  • Jose Altuve: He’s really turned into a power hitter with a 20% HR/FB rate over the past two seasons. Just don’t count on any more steals.
  • Vladimir Guerrero Jr.: Fake News, Fake News
  • Yandy Diaz: He must hate grass the way he scorches balls into it. The craziest thing is that he’s down 9% points but still at 46%.
  • David Peralta: While not the biggest change, he’s being drafted in a range of similar outfielders. Any change could make him stand out.
  • DJ LeMahieu: Stays put. If he hits the same as the past two seasons, no one will complain.
  • Ryan McMahon and Raimel Tapia: Two hitters with a huge home outfield and they are hitting more groundballs. Great.
  • Eric Hosmer: His 2020 flyball changes didn’t seem to stick and he’s back to worm killing.
  • Nick Solak: The lack of elite power and the high groundball rate has me questioning him reaching 20 homers.





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 once, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.

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James Adler
1 year ago

Pardon my ignorance, but why is Vladdy Fake News?

AF
1 year ago
Reply to  James Adler

My guess is he wants people to think it’s fake news and just quickly overlook something like this so that they don’t capitalize on him…

Travis Lmember
1 year ago
Reply to  James Adler

I think it was a joke – all people have talked about regarding Vlad, for 2 years now, is his weight and how good he could be if he starts to lift the ball more. So, when news comes out that confirms these talking points… OP makes a joke b/c it’s too perfect of a narrative this spring. That is used to reduce hyperinflated excitement from Vladdistans.