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How to unlock Kevin Kiermaier’s bat

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Or, how he’s maybe already busting out of that slump.

MLB: Tampa Bay Rays at Atlanta Braves Brett Davis-USA TODAY Sports

In cracking open the Kevin Kiermaier batting line of .200/.308/.289 (78 wRC+) over 16 games this season, you might note that KK currently has a 69% groundball rate and 48% pull rate, both far above his career averages.

Now, in small sample size theater, anything is possible. KK currently has only 52 plate appearances on the season, and it takes 80 balls in play to stabilize such rates. And yet, a trend emerges.

The interesting thing about this observation is that his pull rate on grounders is lower than where it typically resides (52.2% to career 57.0%). This is where pulling the ball is bad for results, and would theoretically mean the rate is higher for line drives and fly balls, which would be very good news if he could control that part.

KK’s hitting the ball on the ground very hard, but his results have been awful.

Typically the average performance on groundballs is around 30 wRC+ and KK has been a bit above that in his career, probably due to speed and batting left handed, at 51 wRC+. That’s on the higher side of sustainable, as when looking into in the past, the leader over like 10+ years and a good number is Ichiro at around 60 wRC+ on grounders; which makes sense.

This year Kiermaier’s at -30 wRC+ on grounders, which is just horrific, even though he’s pulling it less frequently than before, which is the problem with LH batters that can be shifted easily like KK.

In the air, KK is 0 for 4 on flyballs. Sure, he hasn’t hit many, and almost all (3 of the 4)have been to center which is a tough place to get hits. Obviously these flyballs have low BABIPs (average in the low .100s), so you really need to hit homers to provide production on an FB. His career average is 100 wRC+ on flyballs. That’s lowish. He’s not a big power guy but can hit the ball quite hard. Probably in the average to maybe just below range.

Now KK’s ran good on liners at least. He’s hit 6, and is 6 for 6 with 2 doubles and a triple. For liners, BABIP is very high in the mid to upper .600s on average, so he’s been a bit fortunate here. His career average is a 385 wRC+ on liners and this year that’s at 661 in the tiny, fortunate sample. Note: his BABIP is typically extremely high as mid to high .600s is normal with KK running a career .677 rate.

MLB: Tampa Bay Rays at Boston Red Sox
Aug 10, 2020; Boston, Massachusetts, USA; Tampa Bay Rays center fielder Kevin Kiermaier (39) hits an RBI double during the seventh inning against the Boston Red Sox at Fenway Park. Mandatory Credit: Bob DeChiara
Bob DeChiara-USA TODAY Sports

So what’s the deal with KK’s batting line?

Kiermaier absolutely needs to get the ball in the air more. As with most hitters that aren’t the absolutely monstrous sluggers line drives is where you get your production. The best thing about line drives is the spread is pretty narrow. Even the guys who don’t hit the ball hard average wRC+ of over 300 and then the absolutely top end guys like Stanton put up 400 wRC+ where flyballs depend almost entirely on your game power.

And KK should get the ball in the air more. He should also get far better results on his balls on the ground than he has. So there is some hope for better results. Results combining the line drives and flyballs has been pretty neutral, but if he ran anywhere close where he’s typically ran on grounders he would add roughly 2 hits and add almost .050 of each BA/OBP/SLG and almost 20 points of wRC+ putting him right around league average with the bat.

Now, most of this is all based on his results staying where they have, but the gains really coming from his walk rate right now.

Kiermaier is striking out 1-2% more often, but he’s walking almost twice as often as he has in his career (6.7% career and 13.5% this season). He’s whiffing as much as he has the last couple of years (13.6% compared to 14.3% and 12.5%) while his out of zone swing rate is far lower (25.8% vs 37.9% last year), which is a good place to start.

It’s also worth noting KK’s still swinging at roughly the same of pitches in the zone (72.3% compared to 75.5% and 73.0%). So, slightly less but more than made up by not chasing. This has caused his overall swing rate to fall from 50-55% to 46.3%; the Zone rate is pretty much the same as last year (43.9% to 44.2%).

MLB: AUG 07 Yankees at Rays
Kevin Kiermaier (39) of the Rays is walked and he flips his bat towards the dugout during the game between the New York Yankees and Tampa Bay Rays on August 07, 2020 at Tropicana Field in St. Petersburg, FL.
Photo by Cliff Welch/Icon Sportswire via Getty Images

As a concluding thought: xwOBA is quite positive about KK’s work with the bat. His season total is a .269 wOBA but has garnered a .347 xwOBA, and Kiermaier has hit better than he has in the recent past so far this year. Is this a blip or some real change with the walk rate specifically? I’m not sure. It’s something to keep an eye out on.

If Kiermaier is not currently breaking out of what could be perceived as a slump to start the year, he may just be another victim of the league-wide suppression of base hits, which The Ringer explored earlier this week. However, while BABIP is down across the league — like absurdly down — grounders shouldn’t really be affected, which is how KK is hitting this year (unless the defense/shifting went up in ineffectiveness over the winter by a lot; that seems not likely). Groundball BABIP leaguewide is down only .015 points beyond the normal range.

This is far more words I ever thought about writing about KK right now and I’m not sure it’s really all that informative, but it’s there. It’s really all about KK’s 13.5% walk rate, I think. Thanks insomnia.