There was a lot of discussion last year about Christian Yelich’s transformation into an NL MVP and other-worldly hitter for the Milwaukee Brewers.
People all over were trying to figure out the lanky outfielder hit more home runs in the second half (25) of 2018 than he ever had in an entire season (21) - finishing the year with 36 bombs, behind only a pair of “Coors Field” hitters for tops in the National League.
But it wasn’t just the home runs. It was consistent rockets off the bat that led him to a .326/.402/.598/1.000 slash line, a league-leading 166 wRC+, and a Bonds-esque September, when he sported an absurd .804 slugging percentage. Pitchers could not find a way to slow Yelich down, short of simply throwing more balls out of the zone.
Here’s my two cents on the subject: Yelich morphed his approach into an aggressive, “bat head in front” attack mode instead of his traditional “let the ball travel” and “play pepper” style of swing.
Most pundits assumed Yelich’s rise in power and overall production had something to do with the “launch angle revolution.” Many hitters have concentrated on creating an uppercut swing to match the downward plane of a pitched ball, avoid grounders (which usually turn into outs), and hit the ball out of the park.
It makes sense – both the application of the theory and the belief that THIS is what was boosting Yelich’s performance. Things aren’t always as they seem.
As people would find out, Yelich’s typical bat path has not changed. His launch angle remained at 4.7 degrees, the exact same as 2017 when he hit just 18 home runs with an .807 OPS with the Miami Marlins. That showed he has not altered his swing to get greater lift as many have, since his 4.7 launch angle in 2018 ranked as the 11th-lowest out of 228 players.
With that said, his ground ball percentage (GB%) of 51.8% last season was easily the lowest of his six years in MLB – nearly six percentage points lower than his career average. Clearly, that means his line drive percentage (LD%) and fly ball percentage (FB%) were above his career norms last season with the Brewers.
But how did this happen? What led to a shift in the types of batted balls if his swing wasn’t altered at all? As mentioned earlier, it comes down to a change in approach and the impact the approach has on WHEN the bat makes contact with the baseball.
The image below shows how this factors into creating more line drives, deeper fly balls, and even harder contact. Significant improvement without the risk of altering the mechanics of his swing, which have cause plenty of hitters to become worse for the wear.
By being more aggressive and looking to swing earlier, Yelich’s bat reaches to a better angle upon contact of the baseball. Even with Yelich having a more level swing than most of his counterparts, the natural path still brings the stick upward as the hands progress through the zone. So connecting sooner, when the bat is now ascending, results in more frequent liners and fly balls.
Part of that aggressiveness was geared toward an emphasis on getting the bat head out in front of his body more often, leading to a greater percentage of pulled baseballs and knocks to center field. In the past, Yelich was content with letting the ball get deeper in the zone, causing him to make contact with the ball prior to his bat “ascending” toward the baseball.
Hence, last season, Yelich had the lowest percentage of batted balls hit to the opposite field in his career (27%). That was 2.1% lower than his career average.
Yelich went on the offensive as the year went on, jumping on more first pitches than ever before in his career. In April of 2018, Yelich had a 20% first-pitch-swing rate. By July it jumped to 30% and in August above 40%. It’s interesting, but still doesn’t necessarily answer any questions.
Yelich truly has a fantastic swing with a smooth, repeatable, consistent form (soft front landing, hands short to the ball, back knee collapse, etc.) – no wasted movement. With such a fantastic swing, his timing adjustment allowed him to hit the barrel of the bat more often – meaning a higher percentage of hard hit balls - without actually changing his swing.
Last year, Yelich owned a barrel percentage of 12.9% - the percentage of batted balls he hit with the barrel. That was 3.2% higher than his previous high. If you’ve hit a ball with the barrel of a wood bat, the way the ball jumps is absolutely amazing (and you feel almost nothing). His altered approach turned a dangerous swing into a lethal one.
The increase in barrels led to the highest hard-hit percentage of his career at 47.6% - an increase of 9.6% over his previous best season per Fangraphs. It also led Yelich to be among MLB’s best when it comes to exit velocity. Only a matter of time before those constant lasers off the bat did major damage.
When you add everything up – less contact in the back of the swing, better contact angles, harder contact, more consistent barrels – it leads to a 35% HR/FB percentage, the best in MLB last season.
Thus, when Yelich was making contact, he was doing so with such increased efficiency and impact that it created unmatched power. He still had his near-perfect swing, but with a natural ability to lift more often on pitches inside and over the middle of the plate.
At the same time, his ordinary bat path allows him to hit outside pitches hard the other way as he keeps the bat in the hitting zone for an extended period of time. This also separates him from the extreme launch guys in terms of more consistent contact on a variety of pitches.
The questions for 2019 will be, “What adjustments will pitchers make?” and “Will Yelich be able to re-adjust to their strategies?” Because Yelich only needs to alter his approach and/or timing – not his actual swing – my money is on the 2018 NL MVP being in the conversation once again for the Milwaukee Brewers.
Statistics courtesy of Fangraphs and Baseball Savant