How Christian Yelich is sustaining his power surge

Much has been made of Christian Yelich’s power surge since he joined the Brewers. The latest buzz around Yelich comes after he once again had a superhuman night at the plate, belting three home runs on Monday night as the Brewers Yelich beat the Cardinals 10-7. He would follow that up by launching another bomb in Tuesday night’s contest. Cardinals skipper Mike Shildt said he’s never seen anything like what Yelich is doing.

We’ve established how Yelich turned into an unstoppable dinger machine down the stretch last year. He has always hit the ball extremely hard. Despite not hitting many fly balls, the balls he did hit in the air were crushed, thus the high homer total.

The conclusion I had previously reached was that while Yelich’s newfound power was legit, matching his 2018 power numbers was very unlikely. He probably wouldn’t be a consistent 30 home run hitter moving forward, with a total in the mid-20s seeming more plausible. Flash forward to today, and Yelich has already hit nine long balls in 83 plate appearances, putting him on pace for roughly 60 home runs this season. He’s not going to reach that lofty total (although I should probably stop ruling anything out at this point), but it’s become clear in the early going that Yelich has picked up right where he left off, if not gotten better.

Once again, the question is: how is he doing it? This time, the answer is much more simple. For many years, baseball pundits wondered what would be possible if Yelich were to join the famous “Launch Angle Revolution” and hit more fly balls. While Yelich finally tapped into his power last season, this wasn’t why it happened. He simply hit the ball hard in general (and had a little bit of good fortune).

This year is a different story. Yelich is still hitting the ball hard—harder than ever, in fact. His average exit velocity is 95 miles per hour, and his hard-hit rate is a mind-blowing 56%. However, something has changed. Whether it’s by design or not, Yelich has finally started to lift the ball more frequently. His average launch angle has shot up to 14.9 degrees, a significant jump from his previous career-high of 4.7 degrees. At first glance, it’s easy to dismiss this as a small sample size outlier. After all, Yasmani Grandal currently has a 6.7-degree launch angle, but has had a launch angle of 11 degrees or higher in each of his past four seasons. In Yelich’s case, however, the dramatic change might be more predictive.

Baseball Savant

Yelich has put 58 balls into play this season. He has never managed a launch angle this high over a stretch of 50 batted balls throughout his entire career. His launch angle did spike briefly toward the end of the 2016 campaign, but it was a few degrees lower than it has been thus far in 2019. Furthermore, this year’s increase is actually a continuation of a trend that began for Yelich down the stretch last season. In August, his launch angle jumped to 8 degrees compared to -1 degrees in July. This was not a temporary increase, either. His launch angle stayed at 8 degrees in September, and it has since climbed to where it sits now. This gives us some reason to believe that it’s sustainable.

Likewise, Yelich’s batted ball numbers have changed drastically. For his entire career, he’s been a hitter who hits tons of ground balls and doesn’t hit the ball in the air very often. So far, that hasn’t been the case.

FanGraphs

Yelich’s fly ball rate has spiked to 39.6%, a whopping 16% increase from last season. His ground ball rate, while still higher than the average player, has dropped from 51.8% to 41.3%. If it stays close to that rate, it will be the first season of Yelich’s career in which he has posted a grounder rate below 50%.

This is important because Yelich was hitting fly balls over the fence last season at an unsustainable rate. His HR/FB ratio was 35%, and there is only one known example of a player managing such a high rate for multiple seasons in a row (Ryan Howard). This was the main reason to expect a slight drop in Yelich’s home run total. However, if he continues hitting more fly balls, a regression in the HR/FB department won’t lower his home run total. In fact, Yelich could hit more homers than he did last season.

Last season, 103 of Yelich’s 441 batted balls (23.5%) were fly balls, and 35% of those fly balls were home runs. If his HR/FB drops to about 25%, his home run total decreases to 26. However, if Yelich were to continue hitting fly balls at the rate he has so far this season, it increases to 42 home runs. That’s how significant of an increase this is and why it could have a huge effect if he keeps it up. His increased launch angle and fly ball rate could potentially turn Yelich into a consistent 40-homer threat.

This could very well be a small-sample size anomaly, and Yelich’s launch angle and fly ball rate could trend back toward his career norms. However, the evidence suggests that he’s continuing to get better, and at this point, we shouldn’t be ruling anything out. We may not have seen peak Christian Yelich yet, and that’s a scary thought for opposing pitchers.

Statistics are courtesy of Baseball Savant and FanGraphs and are updated as of April 17.