Where Did Ketel Marte’s Power Go?

I’m sure plenty of us would like to simply forget that 2020 ever happened. In this fictional world where a Men In Black neuralyzer is used to erase the memory of the last 12 months, Ketel Marte would be feeling pretty good about his previous season. 2019 was a big year for Marte. He posted a 150 wRC+ and accumulated 7.0 WAR, both easily career highs, and earned a fourth place finish in the NL MVP voting. With last year wiped clean, he’d be looking forward to building off his breakout in 2021 and establishing himself as a bonafide superstar. Instead, the memory of nearly 200 so-so plate appearances in 2020 comes flooding back and all sorts of questions about his true talent level begin to popup.

When compared to his performance prior to 2019, his 2020 season doesn’t seem all that out of place. His power output dropped back to where it was before his breakout, leading to very similar overall offensive contributions to his early career line.

Which season seems like the outlier when put into this context? Of course, it isn’t so easy as simply throwing out his 2019 and settling on a true offensive talent that falls somewhere around 5% below league average. Most of the projection systems think he’ll fall somewhere in between, with some but not all of his power returning.

Marte’s power surge in 2019 was driven by a significant increase in the number of hard hit balls he put in play in the air. He increased his average launch angle from 5.8 degrees in 2018 to 11.5 degrees in 2019. Along with making more authoritative contact more often, those hard hit balls were pulled more often, too. Every single adjustment he made resulted in greater damage when he put the ball in play.

In 2020, the surface level batted ball metrics all looked unchanged from his breakout year. His average exit velocity, average launch angle, and hard hit rate were all essentially the same. His pull rate dropped by nearly four points but was still in the realm of where it was two years ago. Despite all of these stats remaining relatively stable, his ISO dropped to .122, the lowest mark he’s posted in a Diamondbacks uniform.

The first clue as to the whereabouts of his power comes from his barrel rate. That subset of high quality batted balls really dropped off in 2020. Marte’s average exit velocity on fly balls and line drives dropped from 93.5 mph in 2019 to 91.6 mph in 2020. So even though his overall contact authority remained stable, he struggled to elevate his batted balls with elite exit velocity. Of those six batted balls that Marte did barrel up, all of them were classified as a line drive with a launch angle at or below 25 degrees.

Based on Alex Chamberlain’s research into blasts — the most productive subset of barrels — we know that roughly half a batter’s barrels are “weak,” averaging a 1.140 wOBAcon, while the other half are “blasts,” averaging a 1.744 wOBAcon. In 2019, that benchmark held true for Marte; around half of his barreled up balls in play were “blasts.” In 2020, none of his barrels were blasts, and they earned him a good but not great 1.279 wOBAcon.

Marte’s troubles with barreling up his batted balls is only part of what plagued him in 2020. His power output was definitely affected by his inability to reach his peak batted ball quality as often. But he also struggled to convert much of his non-barreled, solid contact into productive batted balls. These launch angle histogram charts show how his hard hit rate has distributed to various batted ball types.

First, for 2019:

And then, 2020:

In 2019, much of his hard contact was clustered around the most productive launch angles, between 15 and 25 degrees. But in 2020, his launch angle distribution doesn’t have that nice peak around 25 degrees and far more of his hard contact came on balls hit on the ground. It all averages out to be nearly the same profile as far as launch angle and exit velocity are concerned, but the outcomes were significantly weaker.

A glimpse at the spring training Statcast leaderboards is a mixed bag of hope and discouragement. Baseball Savant is posting Statcast data from 10 different spring training fields, including Salt River Fields, the spring home of the Diamondbacks. Just one other stadium in the Cactus League is reporting Statcast data at this time. Of the Statcast tracked balls in play, Marte owns three of the 15 highest exit velocity batted balls this spring — a 113.6 mph double, and a pair of singles hit at 112.5 mph and 112.2 mph. Those batted balls were hit at 14, five, and seven degree launch angles, respectively. Eight of his 10 batted balls this spring have been hit harder than 95 mph but only one of them has been hit at a launch angle higher than 26 degrees.

All the standard disclaimers about using spring training stats apply, perhaps doubly so since we’re only getting an extremely limited view from Arizona. It’s encouraging to see Marte start off the spring with tons of solid contact, but none of those hard hit balls are getting elevated, at least so far. I’m not going to assume that this early spring performance will simply continue into the regular season. I’m sure Marte is still working on plenty of tweaks and adjustments as he gets ready for the season. But it is a little concerning to see the issues that sapped him of his power in 2020 continue to manifest a year later, though of course we should remember how small both sample sizes are.

The other concern that popped up in 2020 was a significant drop in his walk rate. Marte’s strikeout rate dropped to a career low as well, but the lack of walks was a departure from his previously excellent plate discipline. In a recent media session, he said he put added pressure on himself to get off to a good start last year because of the shortened season. That led to chasing pitches out of the zone more often. His chase rate did go up a hair in 2020, but he was also a lot less aggressive at the plate. His swing rate on pitches in the zone fell more than 10 points from 2019. He made contact more often when he did swing, which is one reason why his strikeout rate fell. But that selective approach didn’t continue once he got deep in the count. In three-ball counts, his swing rate ballooned to 72.7%. Feeling the pressure to make something happen in every single at-bat led to an extremely walk-averse approach and some poor swing decisions.

With a full season on the horizon, and the weight of each plate appearance lessened, I’d expect his plate discipline should return to his established norms. Instead, he has to deal with the pressure of proving the power he displayed two years ago wasn’t an aberration. Marte has the tools to be an offensive force at the plate, but he needs to make the necessary adjustments to unlock that power again.