Evaluating the 2014 Hitters: Kevin Kiermaier

In the first part of this series I took a look at Ben Zobrist, but today I want to turn to the guy that had the second most batting runs for the Rays in 2014. Kevin Kiermaier was a revelation coming from relative obscurity and little prospect fanfare to become an everyday player this past season. Most folks didn’t see him being much of a stick, but he came out swinging showing uncharacteristic power and some ability to spray the ball around:

On the left you have his spray chart courtesy of Fangraphs and on the right you’ll find  batted ball distributions via Baseball-Reference for Kiermaier and also for the American League average with an emphasis on only lefties for the direction. It’s a bit of trivia, but there were only 37 homers hit by American League lefties to the opposite field and Kiermaier had two of them. You can see that they look like wall-scrapers over Crawford’s Corner, but even if those don’t get out that’s at least a double and maybe a triple if it falls shy of the wall.  While he uses the entire field pretty well, what you’re looking at is a pull-heavy approach when the ball is on the ground and a lot of mostly lazy flyballs to the opposite field. He has shown a real aptitude for being able to bunt for a base hit which should dissuade defenses from over-shifting all that much which should help balls continue to sneak through.

He leverages his world class speed quite well by keeping the ball on the ground more than league average as shown by his better than average BABIP and his production on balls in play (wOBAcon or wOBAcon+) show him around 27% better than league average when the ball is on the ground. Those high fly balls manifest themselves in a lower than league average BABIP, but he still saw production around 20% higher than the norm, while his line drives play closer to his peers. He profiles similarly to his lefty peers in the American League when it comes to spraying the ball around to the various fields which manifests mostly in his pull and oppo approaches. He’s not as good when the ball ends up going up the middle with depressed BABIP rates and a wOBA+ that is lower than league average.

I hope you’re familiar with the above image by now. The blue line shows his park-adjusted expected wRC+ over a 50-Plate Appearance trendline. These expectations come from the Matchup Tool created by myself and Ian Malinowski that regress career platoon splits for the batter and all pitchers faced while incorporating Steamer projections and a Log5 method of comparing each player’s expected output. The red line shows 50-PA trends for his actual wRC+ which I have park adjusted based on the homefield for each PA and have calculated using the 2014 weights.

Dude came out like a house on fire. After an initial adjustment period he steadily climbed back into being a well above average hitter up until around August 1st when he steadily began to fall off. His worst slump of the year was answered with a gradual incline back to the norm where he mostly oscillated around what we should have expected all along. The early performance boosted his overall line to around nine percentage points better than league average which clearly bested expectations. Batters with bad habits have the advantage early in their careers, but once word gets around it’s necessary to combat what pitchers are doing to exploit those weaknesses. The vast majority of ball players are never able to hide their weaknesses well enough to let their strengths play up and I have no idea if Kiermaier is a guy that can make that adjustment, but luckily his glove means that even if he’s the 87 wRC+ guy on the right of that dotted line then he should be able to still be an average player or better. What might be some causes for the change? Let’s start with his plate discipline:

We’re switching from plate appearance to games so the sample isn’t as robust, but we can still see some things going on. Each line is compared to his weighted-average overall figure for that statistic. For example, he swung at just shy of 30% of pitches that were out of the zone on the year and you can have a good idea of how he was able to stay within his zone or when he was apt to expand. It’s encouraging to see his zone contact (ZContact) rate finish the year stronger than where he was for most of the season and you can get a good idea of how things changed. It’s also encouraging to see him seemingly be able to reign in when he starts expanding too much giving hope that he is able to cover some of his holes. It’s ambiguous, but I dislike seeing his O-Contact rate increase over the course of the year. On the one hand it’s possible that he’s putting pitches that are just off the plate into play and maybe that’s good contact, but often this is weak stuff and if he’s making contact more it may be giving him the impression that he should continue to go out of the zone. It’s tough to draw many conclusions from this so let’s see if we can find anything in the heat maps.

I probably haven’t give him the praise he deserves, but I want to take a moment to thank Jeff Zimmerman for all he does at Baseball Heatmaps. None of this stuff would be possible without his tireless efforts.

Kiermaier doesn’t have any plate appearances prior to this season so it’s impossible to compare him to what he has done previously so let’s compare the good first half with the less good second half to get an idea of where things changed. Keep in mind that this is going to lead to much smaller sample sizes, but I think it gives a good idea.

All Pitches


I want to start off looking at all pitches. The top charts show his swing/take percentages versus lefties and righties while the bottom set shows his run values versus each type of pitcher. Remember, we’re comparing his second half to his first half so anywhere that is blue (and so on) is an area where he swung less or created fewer runs in the second half. Anywhere with Red (and so on) is an area where he swung more or created more runs.

Against lefties we can see that he chased above the zone less of the time, except where he didn’t. He had a real issue with the down and away pitch off the plate which also showed up as a weak spot within the zone on his run values. You can also see that he had less success on inside pitches and his chases above the zone hurt more than where he had become better at laying off. Righties had him swinging A LOT more often above the zone which translated to worse results on pitches that are up and out of the zone. He also performed much worse on pitches within the zone, particularly on those over basically any part of the middle third. You probably expect him to struggle with lefties, but it’s discouraging to see that much worse results, especially with in the zone, against righties. Let’s break it down by each pitch type to get an idea of what might be happening.

Fastballs (2/4-Seamers, Cutters, Sinkers)


We see that the above the strike zone issues are mostly tied to the fastball. Against lefties he did a much better job of laying off high heaters except where he didn’t and those show up in the results based on whether he was able to stay disciplined outside of the zone or not. We also see a couple of cooler spots on the inner and outer thirds. Lefties seem to do a good job of keeping him off balance working inside and out, but he’s not bereft of ability as he does have some locations where he improved including both of the upper corners within the zone and down the middle of almost the entirety of the zone. That discipline did not carry over to righties as he became ultra aggressive chasing up and out of the zone on fastballs, though his results on these pitches was only slightly worse than his first half sample. Where he did struggle is in that dickhole region where he was quite a bit worse. Righties seem to be able to have some success when they pound him inside, especially if they can elevate the fastball. The success on away pitches jibes with his opposite field ability profiled above, but it’s hard to have success when opposite-handed pitchers can get in your kitchen like that.

Breaking Balls (Curves, Sliders, Spike Curves)


The extreme colors involved here should give the notion that we’re dealing with much smaller sample sizes here. He showed a couple of zones against lefties where he just refused to swing over the second half, and a couple of smaller ones where he swung much more often. The areas where he was taking more showed a nice increase in results while his swinging more sections did not. He performed pretty similarly if not slightly better against lefty breaking balls in the second half, elsewhere. Righties got him to chase a ton more inside, but he did show better ability to lay off the breakers that came in above and below the zone. It’s also nice to see him swinging much more often at those mistake breaking balls that are elevated and over the middle of the plate. The results were a mixed bag of improvement and decline, but those are pitches that should get whacked. You can see that he fared much worse throughout the zone against the righty breaking ball with particular trouble up and away and the entire down and in quadrant. That’s a problem.

Change Ups (Change Ups, Splitters)


He only saw a handful of change ups from lefties (on the left) in either sample so let’s move on from that. He chased off the plate away less often in the second half which is good and you can see this show up in the results on pitches away, though off the plate is another story. He also had (much) less success on the entire inner half.

Kevin Kiermaier had a transcendent rookie season, but I think that it would be foolish to expect the first half bat to play full time. Without fixing any of the many issues he has with both pitch and zone recognition you’re looking at around a 90 – 100 wRC+ for the player which isn’t ideal, particularly if he’s in a corner, but the glove allows him to still eclipse the contributions of an average player and if the bat plays then you’re talking about a borderline all star. I’m excited to see which Kevin shows up in 2014, and I’m setting myself up for success by keeping the bar low and reasonable.

About Jason Hanselman

Rays fan.
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