Christian Yelich Turned Into Joey Gallo for a Year

In 2017, Christian Yelich finished his last season as a Miami Marlin with a 117 wRC+. That figure, along with the help of his owner-friendly contract, was enough to make him a highly sought-after trade chip — valuable enough for Milwaukee to send the then-No. 13, No. 52, and No. 87 prospects in baseball to acquire his services. Yelich was widely recognized as an excellent baserunner and at least a passable defensive outfielder. But the Brewers were acquiring him for his bat, and they felt his offense from the previous season helped justify the price they were paying.

Fast forward three years, and there are a different set of expectations for Yelich. This winter, he’s coming off a season which he finished with a 112 wRC+, not far from that final season in Miami. But after back-to-back seasons in which he posted a 170 wRC+ and 15.4 WAR — both tops in the National League in that timeframe — and finished in the top two in the MVP voting, that number now looks like a disappointment. There were some positive aspects of his 2020: He walked more than 18% of the time, and while his .225 ISO was below the standard he’d set in his previous two seasons, it still leads all of his Marlins seasons by a substantial margin. But while that helped him maintain an above-average wOBA, they obfuscate a season full of bizarre and unexpected developments for the 28-year-old outfielder.

Yelich hit just .205 in 2020, a full 77 points worse than he’d done in any other season. His stratospheric walk rate was able to save his on-base percentage (.356), presenting a good lesson in why we tend not to pay much mind to batting average alone. But a drop like this for someone who was previously a .300 hitter for his career is startling. This wasn’t just a matter of small-sample batted ball luck being unfriendly, either; a .259 BABIP is low, especially for Yelich, but it isn’t the main culprit. That would be his strikeout rate, which skyrocketed to 30.8%, more than 10 points higher than his career average coming into the year. We’ve learned hitters can succeed on some level while whiffing that much if they also walk at a high clip and hit for power, but a goofy .205/.358/.430 line is something we expect to see from a three-true-outcomes hitter like Joey Gallo.

What made Yelich so different in 2020? As you can gather from the outlandish walk rate, he began swinging less — much less. He cut his swing rate down from 45.2% in 2019 to 34.6% last year, a drop that was the biggest of any hitter in baseball. Since he wasn’t particularly aggressive to begin with, that was enough to get him the second-lowest swing rate in the majors. Your instinct may be to attribute some of that to the short season not allowing as much time for hitters to level out some odd numbers. But according to Yelich’s rolling averages, he was actually getting more extreme as the season went on, not less:

If you’ve followed my work here with any regularity — and what a chilling thought that is — you may remember I explored a similar swing rate/strikeouts puzzle with another star hitter back in August. At the time, Mike Trout’s strikeout and walk rates had diverged to their worst rates in years despite the fact that he was swinging at fewer pitches than ever before. The problem was that pitchers were throwing Trout too many strikes for him to get away with that level of selectivity and were repeatedly forcing him into disadvantageous counts that led to an increase in whiffs.

That isn’t what’s happening here. First of all, Yelich has good reason to exercise more patience than ever, because he’s seeing fewer strikes than ever. Following his MVP season in 2018, the percentage of strikes he saw fell from a career average of 43.4% down to 35.9%, the largest drop for any hitter that year. It took Yelich some time to adjust to that, but he did eventually; as you can tell from the above graph, his aggressiveness began to dip significantly a little more than 100 games into 2019. Pitchers threw Yelich just as few strikes this year, and he responded by dropping his swing rate even more dramatically. Often, he was rewarded: His walk rate rose to the fifth-highest mark of any qualified hitter. Unlike with Trout, pitchers never responded to Yelich’s extra patience by peppering him with strikes. In fact, he fell behind in counts less often in 2020 than he ever had in his career.

All of that sounds like great news, but it still leaves us with a disturbing question: What caused all of those strikeouts? The obvious issue is whiffs. Yelich missed on 33.6% of the swings he took in 2020, a five-point jump from the year before and nearly 10 points above his career average. A whiff rate like that lands him in the 12th percentile of all hitters, right next to Aaron Judge. Again, that is not where we expect to see Yelich. He was never David Fletcher, but he’s been slightly above-average at making contact for most of his career. The swing overhaul he’s made in recent years to generate more power has made whiffs occur at a higher rate, but it’s doubtful he ever expected it to reach this point.

Finding what’s responsible for all those extra whiffs is rather easy. Coming off his 2019 numbers, Yelich’s swing-and-miss rate against breaking pitches hardly budged, and his whiff rate against offspeed pitches actually dropped slightly. Against fastballs, though, Yelich’s whiff rate climbed from 16.4% to 25.2%. When you dig through more of the data, that spike makes sense. Here’s how his swing rate chart against fastballs changed from 2019 to ’20:

There’s a reason one of the most significant advancements in pitching instruction in recent years has involved asking hurlers to aim high with their fastballs: That’s where hitters have the hardest time making contact. And during a year in which Yelich suddenly had a hard time hitting fastballs, look at where he was focusing many of his swings. The middle-high section of the strike zone is the only area in which he became more aggressive in 2020, and he continued to chase fastballs above his waist even as he effectively eliminated swinging at everything else. By shifting his swing decisions away from where he could do the most damage and into areas where he’d be most vulnerable to whiffs, Yelich was the least potent he’s ever been against fastballs. His .382 wOBA against hard stuff was a 76-point drop from the previous season and his lowest since his rookie year, and his .400 xwOBA against fastballs was the lowest he’s ever produced.

Yelich’s luck against fastballs was at its worst when the count got to two strikes. According to Baseball Savant, he saw fastballs on around 48% of his two-strike pitches this year, which is within a few points of how often he’s seen them in that spot most of his career, including in 2019. Throughout his career, he has tended to swing and miss at fastballs in two-strike counts about 16% of the time. In 2020, that whiff rate practically doubled, shooting all the way up to 30.1%. Those struggles against fastballs led to Yelich striking out in over 53% of two-strike plate appearances, a number far above anything he’d ever approached before.

Strikeouts were only a part of Yelich’s issues in 2020, but fortunately for him, his drop in batted ball luck should be easy enough to rebound. Despite his struggles, he still produced 99th-percentile exit velocity and 98th-percentile hard-hit rates, with his numbers in both categories representing the best of his career. He also maintained the lofty HR/FB% he held over his previous two seasons, and while his ground-ball rate spiked from 2019, it was still lower than he had in any other previous season. Yelich can still tear the cover off the ball, just as long as he’s actually swinging the bat and making contact.

Whether either of the latter points stabilize will be interesting to watch for, because while the strikeout problems seem to have more of a direct link to Yelich’s performance against fastballs than his newfound general passivity, I still don’t believe it’s pure coincidence that he saw a sudden spike in strikeouts at the same time that he dramatically changed his approach. He could reverse course again next year, but history says it’s doubtful; of the 37 hitters since 2012 who have cut their swing percentages by at least six points from one year to the next, just seven of those recovered even half of that reduction in the following season. If a player has decided to become more passive, he usually isn’t going to turn back.

Yelich isn’t the usual hitter. He possesses a combination of contact, power and vision that most players can only dream of, and he’s spent the past few years actively tinkering with his game to try to find out how to maximize those gifts. It didn’t work in 2020, but in his defense, what did? Now, he has the offseason to re-evaluate all of this and more. As puzzling as Yelich’s season was, I’d wait a bit longer to adjust your expectations of him.