Max Kepler’s Not-So-Obvious Breakout

At first glance, Max Kepler had a very Max Kepler year. In several key categories, he was pretty much the same player he’s always been, which is to say that he once again came close to, but failed to achieve, league average offensive output:

Where it really counts, in wOBA and wRC+, Kepler has been consistent—but consistently underwhelming. Skimming over these results, one would be inclined to conclude that the Twins are still waiting for Kepler to break out.

But ask anyone in the Twins front office, and they’d likely say that Kepler broke out last season, beneath our noses. And indeed, looking under the hood, we find several reasons to reach that same conclusion for ourselves:

There were improvements across the board—and improvements that weren’t so obvious based on the data presented in the first table. But why didn’t these improvements translate into actual results? The answer lies in Kepler’s platoon split history.

Entering 2018, Kepler was probably not someone the Twins expected to feel great about having at the plate when there was a lefty on the mound. In fact, here is a list of the five left-handed hitters with the worst wRC+ against left-handed pitching from 2016-17 (min. 250 plate appearances):

Kepler was the very worst, and it wasn’t particularly close. The good news for him, and indeed, the primary reason he found himself in a major league lineup nearly every day in 2018, was that he entered the year with a healthy 112 wRC+ against righties. That, combined with his youth and impressive set of tools, made him a compelling player, albeit an imperfect one who seemed destined for a future as a platoon player.

But Kepler, evidently, wasn’t ready to submit to that narrative. Here’s how he fared in some key areas against lefties in 2018, compared to 2016-17:

He increased his walk rate, decreased his strikeout rate, halved his GB/FB ratio, and hit the ball significantly harder. None of these improvements are easy to fake, so Kepler is probably no longer in the conversation for baseball’s worst left-handed hitter against left-handed pitching.

Yet the question remains: How come this newfound success against lefties didn’t translate into an obvious breakout season? His performance against righties in those same categories completes our picture:

Again we see improvement in areas that are hard to fake, but we also see a 63 point decline in BABIP, which is the metric on this list that is most susceptible to variation caused by random chance. Kepler was able to produce a 113 wRC+ against righties in 2016-17 with worse peripherals than he had in 2018, yet he was somehow 18 percent worse against them last season. That just doesn’t add up, and it’s something that seems unlikely to continue.

Instead, look for Kepler to improve upon his pre-2018 112 wRC+ against righties, and for his league-average performance against lefties in 2018 to become more or less his new norm. All told, Kepler looks like a much improved hitter, and one who should be solidly above average in 2019, despite what his below-average results might otherwise suggest. He should be a nice, underrated buy in fantasy points leagues this season.