In Which the Value of Kevin Kiermaier is Probably Grossly Overstated

Jose Abreu has seemed a virtual lock for the AL Rookie of the Year Award ever since Masahiro Tanaka went down with what could be a season-ending elbow injury. Abreu has done nothing but hit the hell out of the ball since storming into the Majors after fine-tuning his craft in Cuba. Rookies like Brock Holt and George Springer have had nice seasons of their own, to be sure, but they’re certainly no challengers to the might of Abreu.

Then, of course, there’s the best rookie that mostly nobody’s heard of. Let’s say hello to Mr. Kevin Kiermaier. A 31^st round pick in 2010, Kiermaier fought his way through the minors and finally, after a single game appearance last year, was called up for good on May 17^th. He’s since appeared in every game since May 31^st.  In 57 games (198 plate appearances), he’s hit .311/.362/.544. More importantly, he’s produced a .391 wOBA and 157 wRC+. Those are certainly pretty numbers. But can he keep it up? Kiermaier hit well at almost every level in the minors, but was always known for his superb glove work. Let’s look at his and Abreu’s numbers together, shall we? All stats herein are as they were prior to the inception of action on Monday the 29^th.

Player	Games	PA	wOBA	wRC+	HR	K%	UZR	DRS	fWAR
Abreu	91	393	.406	159	30	23.9%	1.1	-5	3.4
Keirmaier	57	198	.391	157	8	18.7%	10.5	8	3.1

Abreu is numerically the greater offensive producer, if only by a slim margin. He’s only out-produced Kiermaier relative to the league (wRC+) by two points, but his wOBA is indicative of the fact that he’s driving the bar a lot further (.619 slugging percentage versus Kiermaier’s .544). Yet while chicks most certainly dig the long ball, it isn’t everything.

Kiermaier’s .362 OBP is a fantastic mark. It’s about twenty points higher than Abreu’s, and it’s incredibly beneficial for his spot in the lineup. For all his famous lineup tinkering, Joe Maddon has been primarily using Kiermaier out of the 9 spot of late. He even went as far as batting the pitcher (Alex Cobb) eighth on July 23^rd in an inter-league game against the Cardinals so that Kiermaier could bat ninth. Putting him there allows him to serve as what basically amounts to a second leadoff hitter when the lineup turns over, and there’s one more runner on base for the big boppers in the heart of the order.

Kiermaier also is much more of a two-way player. UZR and DRS are both very pleased with his defensive skill set. That’s not a surprise, as many scouting reports on Kiermaier always gave glowing reviews of his instincts and range in the field. It’s that defense that has allowed him to be right on Abreu’s tail in total value, in far fewer games. While UZR says that Abreu isn’t a total loss at first base, DRS says he leaves much to be desired. Naturally, first basemen traditionally aren’t employed for their gloves, but nobody complains when someone like Carlos Santana comes along and dazzles on both sides of the ball.

Now, the hard part. We want to extrapolate Kiermaier’s value over the same time span that Abreu’s accrued his, but how? It would be easy to simple do it over the same number of games played. However, “games played” doesn’t account for late-inning substitutions, or early exits. A better (but still not perfect) way of looking at it would be to extrapolate it over innings played. This is still not perfect, as a batter can hit in the top of an inning and then be replaced in the field in the bottom, and vice versa. However, I’m not a good enough statistician to develop my own metric for this (check back with me in a few months) and I can’t find anything out there to show just how much time a player has seen.

I used Baseball-Reference’s game logs for this, as they have a count of how many innings the player saw. Here’s how these numbers work out.

Player	Innings Played	PA	fWAR	fWAR/I
Abreu	812	393	3.4	~ .00418
Kiermaier	464	198	3.1	~ .00668

This is far from an exact science. Abreu and Kiermaier didn’t produce exactly that many wins every inning they plated, but it’s how the numbers work out. Now, if Kiermaier’s fWAR/I (fWAR per innings played) is multiplied by Abreu’s total innings played, the result is an fWAR total of 5.425. So far this season, Mike Trout leads all of baseball with 5.7 fWAR. Troy Tulowitzki is in second place with 5.1. That’s assuming, of course, that Kiermaier maintains his current level of play. And as I said before, “But can he keep it up?” The answer to that is “I haven’t a clue.” Here’s why.

BABIP	GB%	BA vs. RHP	BA vs. LHP
.353	50.7%	.336	.225

There are two glaring realities. One is that Kiermaier hits a lot of ground balls. His BABIP would seem to indicate that’s he’s getting lucky, and his grounders are finding holes in the infield. For what it’s worth, here’s the league leaders in ground ball rate out of everyone who’s qualified for the batting title. It’s a mixed bag for sure. There are some good hitters around Kiermaier’s range, like Yasiel Puig, Alexei Ramirez and Melky Cabrera. Derek Jeter’s made a heck of a career out of a high ground ball rate and good BABIP. So while that isn’t an immediate cause for concern, it’s something worth watching to be sure. For reference, here’s his Brooks Baseball spray chart on the year.

The other is that southpaws have completely owned him. While right-handers are more common (and Kiermaier certainly has no problem with them), in the age of specialized bullpens it’s one awful quality to have. Managers (and the think-tanks in front offices) are surely catching on to this. Eventually, the scouting report will read to get a lefty reliever to face him in high-leverage situations, if they can. This also, of course, could be a result of small samples sizes. Kiermaier only has 43 plate appearances against lefties, and 155 against right-handers. Another thing to keep an eye on going forward.

However, what Kiermaier is doing is not wholly unsustainable. Players have made livings on putting ground balls in the right spots, and good players at that. However, the projections for the rest of the season aren’t too pretty. ZiPS predicts that he’ll produce a .259/.312/.385 line for the rest of the season. Steamer has him at .257/.311/.382. The projection systems are generally not too far off from reality, but it’s fun to think about what could be. Will Kiermaier end up being a 5-win player? The odds aren’t good. It’s certainly possible, though, and if it does happen prepare yourselves for a wonderful offseason debate on whom the rightful winner of the Rookie of the Year Award really was. In the meantime, let’s marvel at how darn good this former 31^st round pick has been.

Nicolas Stellini is a student, college baseball announcer, and amateur baseball writer. Check him out over at @StelliniTweets.