How Marcell Ozuna soared to stardom

I last wrote about Marcell Ozuna back in December when St. Louis’ five-player trade with the Marlins was first announced. The dek line of that article read:

The Cardinals should expect regression from their latest acquisition in 2018, but they parted with a light prospect haul

I’ll spare you the avalanche of numbers I cited in that piece, but just know that Ozuna was the benefactor of likely unsustainable batted ball luck in 2017. I recall talking to Fish Stripes contributor Aram Leighton–who I interviewed about Cardinals-Marlins trade dialogue earlier in the offseason–shortly after the trade news initially broke. He told me that Ozuna revamped his approach at the plate last year, a claim I certainly won’t deny. Last season, Ozuna posted career highs in walk rate and hard contact rate. Furthermore, his 73.1% swing rate on pitches inside the strike zone was easily a lifetime best while also maintaining a chase percentage of 33.1% to match his career average. Even if regression is anticipated, Ozuna is still arguably the best left fielder in baseball.

Whenever I’m searching for topics to write about, I often find myself scanning over the statlines of various Cardinals players. This week’s FanGraphs exploration led me to stumble upon the following bit from Ozuna’s splits page.

Prior to 2017, Ozuna’s offensive production was 3% below average against right-handed pitchers. As roughly 80% of the outfielder’s career plate appearances have come versus like-handed opponents, Ozuna’s value was capped before he broke out to the tune of a 150 wRC+ against righties in 2017. Surely there had to be more than good fortune to explain a change this drastic.

With three years of Statcast data at our disposal, I looked at Ozuna’s expected wOBA based on his launch angle and exit velocity outputs. Craig Edwards has shown this stat, commonly referred to as xwOBA, to hold more predictive power than most other metrics.

Considering the 45 point disparity between Ozuna’s expected and observed wOBA last year, his performance against righties was likely more impressive on the surface than in reality. Still, his 44 point leap in xwOBA from .318 to .362 is definitely a tangible improvement.

Let’s examine Ozuna’s 2017 campaign in closer detail. According to the strike zone maps available at BrooksBaseball.net, refined plate discipline could be a leading suspect behind his resurgent season. Note the change in his swing percentage on pitches in the circled zone between 2016 and 2017.

In 2016, Ozuna bit 48.7% of the time opposing righties attacked him away. While reducing that figure to below 41% may not seem like much, the above charts also illustrate how that opened Ozuna up to be more aggressive in his wheelhouse: pitches located on the inner-half of the plate. Sure enough, his slugging percentage on pitches in the two leftmost columns skyrocketed from 0.442 to 0.803 last season.

Take this at-bat between Ozuna and Braves reliever Chaz Roe from 2016. After swinging through a slider off the plate to fall behind 1-2 in the count, the former was evidently caught off guard on the ensuing pitch. Ozuna tapped Roe’s inside sinker back to the mound as an “excuse me swing” turned into a 1-4-3 twin killing to retire the side.

via MLB.com:

Contrast that with a 2017 matchup against then-Nationals right-hander Matt Albers, whose 1.62 ERA last year ranked sixth best among qualified relievers. Albers started Ozuna off with a pair of offspeed pitches away, both of which Ozuna laid off to jump ahead in the count, 2-0. When Albers tried to sneak an inside fastball past Ozuna later in the at-bat, the two-time All-Star was ready to pounce on the pitch he was looking for all along. Some 396 feet later, Miami had itself a tie game on Ozuna’s three-run blast.

via MLB.com:

While the Cardinals shouldn’t expect Ozuna to repeat his phenomenal 2017 season, there is ample reason to believe that he made legitimate adjustments at the plate to tap into his offensive upside. Long story short: Ozuna’s overhauled approach has elevated his game in ways that boost my confidence in him going forward.

Get excited, Cardinals Nation. We are less than four weeks out from Opening Day.