Max Kepler is Locked In

It wasn’t that long ago that a sizable portion of Twins Territory was ready to move on from long-time right fielder Max Kepler. Zach put himself in harm’s way when he asked in early June if Kepler should be playing some center field in light of Byron Buxton’s lingering knee issues. Instead of support for that idea, the general tone of the comments section was that the Twins would be better off replacing Kepler on the roster with someone else altogether.

It wasn’t just us at Twinkie Town. Aaron Gleeman wrote an article in The Athletic around the same time, asking how much longer the Twins would let Kepler block Matt Wallner and that prompted a very funny satirical post from Randballs Stu at Twins Daily that said the Twins were keeping Kepler in the lineup just to spit Gleeman.

The context of that chorus was Kepler’s .189/.261/.365 batting line (.272 wOBA, 72 wRC+) through June 19. Kepler’s start to this season reflected a fourth consecutive year in which his offensive production was worse than the one before. 2019’s Bomba Squad breakout was becoming a distant memory that seemed increasingly unlikely to repeat.

On June 20, Kepler drew a walk and homered late in a blowout loss to the Red Sox. The next day, he homered again and also drove in a run with a single. Two days later, he homered again in Detroit. Baseball gives us all sorts of opportunities to make stats sing with arbitrarily chosen endpoints, but, since June 20, Kepler has hit a scorching .284/.337/.561 (.379 wOBA, 146 wRC+) that compares favorably even to his 2019 career year.

Among Twins in that span, only Edouard Julien has been more productive (154 wRC+) and Kepler’s marks rank 24th out of 169 qualified players across MLB.

Better Luck Or Something Different?

There was some reason to think Kepler’s slump through mid-June had been unlucky. He had just a .200 batting average on balls in play (BABIP) that was well below his career .249 level. Better still was that Kepler’s average exit velocity was 91.0 mph, nearly two miles an hour above last season’s 89.1 and easily a career-best. He’d also raised his average launch angle to almost 15 degrees, reversing a multi-year trend of hitting pitches on lower, and less fruitful, angles.

But that’s always been the thing with Kepler. He’d always ran low BABIPs that we could use to convince ourselves he was unlucky, and he’d typically been a bit of a Statcast darling whose x-stats and plate discipline indicated better days to come. But those days never seemed to come. That was the essence of the Kepler conundrum.

Among the 493 batters with at least 1,000 plate appearances in the Statcast era (since 2015), the 17-point gap between Kepler’s .233 batting average and his .250 expected batting average is the 5th-largest. The other names on that end of the list are mostly burly, slow-footed first baseman and catchers, not athletic outfielders.

Despite the seemingly favorable underlying numbers, Max was held down by how often he pulled ground balls, often into the teeth of defensive over shifts, and hit popups. Gleeman detailed how Kepler’s propensity to produce these low-quality balls in play served to undermine his production and limit his ceiling.

Gleeman showed he was one of only three left-handed hitters with a pull rate above 45% and a ground ball rate above 40%. About one of every eight of Kepler’s fly balls was classified as a pop-up, the 6th-most by a lefty since 2015. It wasn’t that he was unlucky. He had earned his stats by frequently making low-quality contact much in the same way the Guardians do.

Higher Quality Contact

We know, thanks to Statcast data, that the most productive batted balls are those that are hit 95 mph or greater (hard hit) and at launch angles between 8 and 32 degrees (sweet spot). Put those together and we get the most productive batted ball category of all, barrels.

In Kepler’s case, sweet spot rate is an interesting indicator because his challenge in the past wasn’t about making contact or even hitting the ball hard, it had been too often topping pitches into the ground or getting under them for weak flyouts.

Here’s Kepler’s rolling sweet spot rate this season:

Lately, he’s been much more effective at hitting the ball on more advantageous angles than he had been earlier in the season. Those have primarily been line drives, which have come at the expense of popups and a few fly balls that would otherwise probably be outs:

As a result of making contact in a more narrow window of launch angles and eliminating some of those easy in play outs, Kepler’s ~46% rolling sweet spot rate right now matches the highest mark of his career, which came in the middle of the 2019 season, as you can see below:

Combine that with the exit velocity gains that I mentioned above and Max’s seasonal barrel rate per plate appearance is currently 9.0%, easily the highest of his career and well above his 5.2% career average.

What Changed?

Kepler was interviewed on the pregame radio broadcast before last Saturday’s game and was asked what he had changed to spur this nice run of success. He said he hadn’t changed anything about his routine or approach (hitting coach David Popkins validated that assessment later) but offered something to the effect that maybe he’d been getting better pitches to hit and been doing more with those opportunities.

The data suggests that there is some truth to that theory. Through June 19, opposing pitchers had thrown 49.6% of their pitches to Kepler in the strike zone. Since June 20, that rate has risen to 52.7%. Even more favorable is that the share of pitches Kepler has faced that are fastballs (four-seamer, sinker, cutter) has also increased slightly from 53.9% to 55.9%. That all seems to support his idea that he’s getting better stuff to hit.

What Kepler has done with those in-zone fastballs has also turned around. Against 192 in-zone fastballs faced prior to June 19, Kepler hit just .161 and slugged .464 (.247 wOBA). (In fairness, his xBA and xSLG against fastballs then were .266 and .626, respectively.) That performance may have contributed to why opposing pitchers have been throwing him a few more fastballs.

Since June 20, though, Max has hit .329 and slugged .722 against heaters, good for .435 wOBA. He may not have changed his approach, but he’s suddenly on fastballs in a much better way than he was early in the season.

Future Outlook

Does this mean that Kepler is fixed and will stay at this level going forward? The odds are probably against that, given the much larger track record over the past couple of years. Line drive rates are also volatile, much more so than other batted ball types. It seems improbable that Kepler has suddenly changed his profile and permanently replaced other less productive batted ball types with liners.

We probably should expect to see opposing pitchers adjust again and reduce the number of hittable fastballs that they challenge him with. To that point, Kepler has hit just .188 and slugged .292 (with the x-stats to match) against breaking pitches during his hot stretch. It’s similar against offspeed pitches, .200, and .314 with supporting x-numbers. They will adjust and he will have to in turn.

But, for the time being, he’s locked in to an extent that we haven’t seen in a few years, and it’s come at a time when the Twins offense has badly needed this kind of production. They’ll certainly take it and we should enjoy it while it lasts.