Hitter FB% Surgers — 8/10/20, A Review by Mike Podhorzer October 21, 2020 I love batted ball distribution changes (hitting more fly balls or ground balls), because they are usually under the hood and require a review of the hitter’s statistical profile to uncover. Typically, when we see a home run breakout, it’s usually because of the obvious — the hitter has raised his HR/FB rate. But that’s not always the case. Sometimes he’s hitting home runs on his flies at the same rate, but simply hitting more fly balls. That’ll get you to the same destination, but following a different route. So in early/mid August, I identified and discussed the hitters that had increased their fly ball rates the most versus 2019. At that point, the sample size was still small, of course, so I was curious how these hitters performed the rest of the way. Did they maintain their FB% spikes or did those marks fall back to their 2019 levels over the rest of the season? Let’s find out. FB% Surgers Name 2019 FB% 2020 FB% Through 8/8 Diff 2020 FB% After 8/8 FB% After 8/8 vs Through 8/8 FB% After 8/8 vs 2019 Niko Goodrum 31.5% 50.0% 18.5% 44.1% -5.9% 12.6% Wilson Ramos 19.2% 34.3% 15.1% 27.3% -7.0% 8.1% Pedro Severino 36.9% 51.7% 14.8% 28.6% -23.1% -8.3% Trevor Story 42.3% 56.5% 14.2% 44.4% -12.1% 2.1% Starlin Castro 33.0% 46.9% 13.9% 33.3% -13.6% 0.3% Max Muncy 38.7% 51.2% 12.5% 38.2% -13.0% -0.5% Matt Chapman 43.1% 55.0% 11.9% 46.9% -8.1% 3.8% Yoan Moncada 34.5% 46.3% 11.8% 33.0% -13.3% -1.5% Wil Myers 35.1% 46.7% 11.6% 36.0% -10.7% 0.9% George Springer 35.7% 47.1% 11.4% 42.0% -5.1% 6.3% Eddie Rosario 42.2% 53.5% 11.3% 44.4% -9.1% 2.2% Fernando Tatis Jr. 30.9% 42.1% 11.2% 33.3% -8.8% 2.4% David Dahl 32.5% 43.2% 10.7% 36.4% -6.8% 3.9% Trea Turner 32.8% 43.2% 10.4% 32.7% -10.5% -0.1% Nolan Arenado 44.7% 54.9% 10.2% 43.5% -11.4% -1.2% Marcus Semien 38.9% 48.9% 10.0% 45.7% -3.2% 6.8% REGRESSION! Once again, that’s the name of the game. No matter how strongly a hitter does in a certain metric over a small sample, the pull of historical performance is simply too strong. All 16 hitters saw their FB% marks decline after their early surge. Of course, those regressions were not equal. One hitter only lost about 3% of fly ball rate, while another lost a whopping 23%. If we look at the last column, we actually find that 11 of the 16 still posted a rest of season FB% that was higher than their 2019 marks. This suggests that even if we were to assume regression off the monster surge early on, the surge itself is meaningful in that hitters have changed their batted ball tendency and the early season spike shouldn’t be completely ignored, even if the rest of season increase versus 2019 isn’t as extreme as the early going. Niko Goodrum was a surprising name to find atop the FB% gainers, as he’s not exactly the big power hitter you would think can take advantage by hitting more fly balls. It looks like he completely sold out for power, as his strikeout rate skyrocketed, while all those fly balls resulted in his BABIP falling below .300. Overall, his wOBA plummeted below .300, so it’s clear that whether this was an intentional change or not, the process did not work for him. While it’s anyone’s guess which version appears next season, I would think the groundballing and line driving version is best. We were so close to a Wilson Ramos FB% breakout! For a plodding catcher with a career 17.9% HR/FB rate, it makes little sense that he has posted a career FB% just under 26%. He likely would have enjoyed far more than just one 20-homer season if he just hit fly balls at a rate you would expect. Woah, guess Pedro Severino used up his 2020 allocation of fly balls super early and decided to nearly stop hitting them the rest of the way. Weird. While a 56.5% FB%, playing half your games at Coors Field, is exciting, it’s typically not a path to hitting success. So it’s not a bad thing that Trevor Story was unable to sustain his extreme early rate, and he ended up posting a rest of season mark right in line with his career. Interestingly, you probably didn’t even realize that he posted a career low HR/FB rate, because if you owned him, you enjoyed those 15 steals, which more than offset the loss of a couple of homers. That early season FB% bump for Starlin Castro meant nothing, as he was right back to near exactly his 2019 level the rest of the way. We don’t want him as an extreme flyballer anyway, as he just doesn’t have the power. Add Max Muncy to the list of guys whose early season FB% surge meant nothing, as his mark fell right back to his 2019 level the rest of the way. If you needed home runs, a 50%+ flyballing Muncy would have been nice! But it wouldn’t have done any favors to his BABIP. Matt Chapman, Yoan Moncada, and Wil Myers all more or less performed the rest of the way similarly to their 2019 levels, meaning their early season fly ball spike wasn’t a sign of things to come. All three do have the power to take advantage, as a drop in BABIP would have been offset by the increase in home runs. George Springer was one of the few who still held onto enough of his FB% gains the rest of the season to post a significantly higher mark than 2019. In fact, this was the first year his FB% climbed above 40%, and amazingly, it marks the fifth straight season his FB% has risen. Predictably, it hurt his BABIP, which set a new career low, but his wOBA still finished at its second highest mark, only below 2019 when he posted a career best HR/FB rate. Eddie Rosario and Fernando Tatis Jr. both ended up holding onto only a couple of percentage points of gains, posting a FB% mark the rest of the way not too far off their 2019 marks. Obviously, both have the power to take advantage of more fly balls, especially Tatis Jr., who now sports a 30.7% HR/FB over his career, which essentially amounts to one full season. Forget the fly balls, will David Dahl ever stay healthy?! My Trea Turner blurb in the initial writeup was as follows: Trea Turner is exactly the type of hitter you don’t want to see raising their FB% mark. Why is he hitting more fly balls? While he does have power, he should be utilizing his speed more and hitting more line drives and ground balls. This is one of the rare times where a higher FB% is likely to result in a lower fantasy value. So what happened since? His FB% over the rest of the season was within 0.1% of his 2019 mark! Obviously, he read my article and realized he should go back to his previous batted ball distribution. Nolan Arenado makes the third Rockies hitter to appear on this list, which is odd. He just had the worst season of his career since his 2013 debut, with both his BABIP and HR/FB rate plummeting. His strikeout rate hit a career best, but that didn’t matter. For the first time ever, he might be a bargain next season. Marcus Semien posted the third largest FB% gain over the rest of the season versus 2019 and finished with a career high. Unfortunately, he couldn’t sustain his career best 2019 HR/FB rate, as it fell right back down below 10%. His power is so tough to project, as he’s posted two mid-teen HR/FB rate seasons, with the rest essentially being between 8% and 10%. It’s anyone’s guess whether we get the mid-teen Semien or high single digit Semien in 2020.