2021 Review: Hitter Pull FB% Leaders

Let’s continue diving into the components of my hitter xHR/FB equation by reviewing the 2021 leaders in Pull FB% (PFB). This is the percentage of a hitter’s fly balls that are pulled. For home runs, the higher the PFB, the better…for the most part (there are always exceptions). Why? In the Statcast era (since 2015), average distance of fly balls by batted ball direction were as follows:

Those are some serious differences solely based on the fly ball’s horizontal direction. Since hitters hit the ball further, on average, when they pull their flies, then a higher rate of pulled flies should typically result in a higher HR/FB rate. So let’s now review the 2021 PFB leaders (minimum 20 fly balls).

Out of the 24 hitters who posted a 40% PFB and higher, 16, or two-thirds, of them posted a higher than league average HR/FB rate. That’s a good illustration of how important PFB is for hitting home runs. It’s not even higher because it’s just one of several components that drive that rate. You could pull all the flies you want, but if you’re a weakling and aren’t hitting them far, they won’t be traveling over the fence for a dinger.

Mike Zunino was the far and away leader in PFB in 2021. That was a surprise, as while he has generally posted above average PFB marks, just once did he even reach 40%. In fact, his 2021 mark was more than double his small sample 2020 mark. So this was one of the big drivers of his career best HR/FB rate. Is it repeatable? Probably not. He’ll likely need to keep his PFB in the 40% range to ensure his HR/FB rate stays in the low-to-mid 20% range and doesn’t fall back into the teens.

Who would have guessed that Ha-seong Kim would be the second pulliest flyballer?! He’s a good example of a pull hitter who didn’t have the strength to make those pulled flies really count. While his average fly ball and line drive distance was league average, his Barrel FB% and Barrel LD% were well below. I’m sure inconsistent playing time didn’t help, and unfortunately, his 2022 playing time outlook remains murky.

Want to know the secret to Jose Ramirez’s transformation into a power guy? It’s the pulled flies. He posted 20% marks in 2015-2016, along with mid-single digit HR/FB rates, then bumped up his PFB into the 30% range, as his HR/FB rate jumped into the mid-teens. Then in 2018, his PFB surged again above 40% and has remained there since. It’s no wonder his HR/FB rates have followed suit, with his two highest career marks these past two seasons. Until and unless he stops pulling his flies, he’ll continue to be good for a mid-teen HR/FB rate.

The pulled fly has also been the driver of Jose Altuve’s transformation into a power hitter. In 2019, his PFB spiked from the low-20% range to the low-30% range, and his HR/FB rate skyrocketed above 20% for the first time. He then posted a career high PFB in 2021, and while his HR/FB rate didn’t quite reach his 2019 peak, it still marked the second highest of his career. The transformation into a pull hitter has also eroded his BABIP skills, so he’s no longer an elite batting average contributor. Combine that with his speed drying up, and Altuve’s gotta keep hitting those bombs to maintain strong fantasy value. That makes him a risk now without the batting average and steals to fall back on.

Gavin Sheets enjoyed quite the solid debut with the White Sox, posting a .352 wOBA and big .256 ISO, driven by a 23.9% HR/FB rate, the latter two marks being professional highs. While he showed the barrel ability and strength to post a high HR/FB rate, it was really the penchant for pulling his flies. Sheets is currently atop the team’s DH depth chart according to our RosterResource page, on the strong side of a platoon with former top prospect Andrew Vaughn. While I like Sheets’ plate discipline and power skills, his reliance on those pulled flies, and the alternatives the Sox have to fill the DH slot makes him a risk. He probably won’t cost too much though, so the downside here isn’t too great.

It wouldn’t be a power-related list without Adalberto Mondesi’s name once again. I’ve talked enough about him on previous lists, so there’s nothing more to say here.

It was a disappointing and injury-riddled season for Mike Moustakas, even though he posted his highest PFB on my file, which goes back to 2015. Unfortunately, his average fly ball and line drive distance dropped to a low, while his Barrel FB% remained well below league average. With a questionable playing time outlook, there are better rebound candidates to speculate on.

This was Anthony Rizzo’s highest PFB, but his lowest xHR/FB rate since 2015, and lowest actual HR/FB rate since 2013. Surprisingly, at least to me, he has only posted a Barrel FB% above the league average twice since 2015 (seven years), coming in 2017 and 2019. We’ll have to see where the free agent ends of signing to determine his attractiveness as a rebound candidate off a disappointing fantasy season.

Jorge Soler has really picked up on the pulled flies the last two seasons, though he hasn’t been able to match his 2019 HR/FB rate. After a slow start, he really turned it on with the Braves, but like Rizzo, is a free agent and his new team will help determine our forecast.