Arizona right-hander Zac Gallen had a terrific 2020 campaign, and his overall numbers would be even more impressive if we could simply just do away with two bad starts in September. Across 72 innings of work, he posted a sparkling 2.75 ERA, 10.25 K/9, 3.23 BB/9 and 1.11 WHIP. Of his 22 earned runs he allowed, half of them came in back to back starts in the final month of the year, when he allowed seven earned runs to Seattle and four to San Francisco. Just for fun here, but if we remove those two starts, Gallen’s ERA on the season would be 1.60. Aside from those two starts, he allowed two or fewer earned runs in every start, and he failed to reach six strikeouts in just one start. Gallen was masterful to say the least in 2020.
Gallen boasts an expansive repertoire with four pitches that he threw at least 16 percent of the time in 2020. He can attack either side of the plate, but for the most part, he lives away to right-handers, and then peppers the lower third of the zone with his changeup and curveball. His fastball typically ends glove side, so he uses that changeup to attack lefties low and away, or force right-handers to swing over the top. Per Baseball Savant, Gallen is above average in terms of pitches on the edge of the zone. The league average is 39 percent, but Gallen clocked in at 48.6 percent last year.
When there’s two strikes, good luck guessing what’s coming, as each of his four main pitches registered at least 14 strikeouts, and posted a whiff rate above 17 percent. His cutter, changeup, and curveball all posted whiff rates above 28 percent!
Take a look at Gallen’s pitch usage by count from 2020, but like I mentioned above, take note mostly of the left-hand side, and even the middle.
He’s comfortable using all four pitches at any time in the count. You love to see that. Furthermore, he was one of just six pitchers that pitched at least 40 innings in 2020 to have not one, not two, not three, but four different pitches with a weighted rating (wFB, wCB, etc.) over 1. Exceptional.
Despite inducing more ground balls than 2019, Gallen had a slight uptick in home runs. Take a look at the graph below, courtesy of Fangraphs, highlighting Gallen’s ground ball rate, fly ball rate and home run metrics.
So what happened? It’s not too often that more ground balls and fewer fly balls results in an increased HR/9 mark. Now, it can be explained, however, it’s not as simple as an increased exit velocity on specifically fly balls and line drives, because that mark actually dropped compared to 2019.
Compared to 2019, we can see a sizable shift in where fly balls were hit against Gallen.
That’s a sizable jump in terms of fly balls being pulled. There wasn’t a differentiating factor in terms of the hard contact, but perhaps with fly balls that were pulled? Spoiler alert: There is.
Furthermore, Gallen was barreled up more in 2020, and you can see the hard hit rates against his changeup and curveball jumped substantially.
Gallen has a deep repertoire and at just 25 years young, he’s posted back-to-back seasons with a sub-3.00 ERA. Sure, his FIP was in the mid-3s, so maybe there’s some regression there, but he should continue to be a top 15 arm in fantasy. Will he post a 28 percent strikeout rate again in 2021? I think he might take a step back and be closer towards 26 percent, but he should be just fine and put up great ratios. Some better luck in the HR/FB realm should benefit Gallen but he’s been damn good since he cracked the bigs. He’s still young, but we have two seasons now of solid results, to the tune of a 2.78 ERA and 1.17 WHIP across 152 innings of work.
He’s currently the 14th starter going off the board, per NFBC data, and while I’d be hesitant to have Gallen lead my staff, he would be an excellent SP2 for any fantasy baseball squad.