The First 15 Starts Of Jordan Zimmermann

Clip art illustration of a Cartoon Tiger with a Missing Tooth

The Tigers struck early this winter, signing Jordan Zimmermann to a five year deal to bring him to Detroit through 2020. Zimmermann, unlike most of the other potential cogs in the upcoming rotation (Verlander, Sanchez, Norris, Greene, Fulmer, Boyd, Pelfrey) was a low variance bet. Zimmermann had been a durable model of consistency since coming back from Tommy John Surgery in 2011 and the Tigers figured he’d be a good bet to maintain his skills into his early 30s.

In a basic sense, things have looked good for Zimmermann this year. His 91 ERA- and 83 FIP- put him somewhere between good #3 starter and solid #2. His full season performance doesn’t reflect that of an ace, but the Tigers didn’t sign him to be an ace. In 95.2 innings, he’s put together a 2.2 fWAR to go along with his 1.3-1.4 WAR if you like RA9, Baseball-Reference, or Baseball Prospectus WAR. In other words, Zimmermann has been successful in 2016 and generally in line with what the Tigers figured they’ve be getting when they put pen to paper last November.

Interestingly, Zimmermann has achieved these results in a manner slightly out of step with his recent approach. His walk rate is an as expected 4.6%, but his strikeout rate is a career low 15.2%. Fewer strikeouts is generally a bad thing, as more balls in play leads to more hits, but Zimmermann has combined that drop in strikeout rate with a decrease in home run rate as well. After allowing 1.07 HR/9 in 2015, Zimmermann has allowed 0.75 HR/9 this year which is a tick below his career average. That works out to 3-4 fewer HR allowed this year based on the lower HR/9 rate. Add that to a slightly higher pop up rate compare to last year and it’s easy to see how Zimmermann has survived more balls in play.

The lower home run rate and higher pop up rate aren’t at all unprecedented for Zimmermann, so while we shouldn’t over emphasize 95 innings of work, we’re not talking about crazy BABIP suppression or something like that. You’re worried about the drop in strikeouts, but you’re not worried that this is a totally implausible way to succeed. When the ball has been put in play, he’s allowing a little bit harder contact than last year, but we’re not talking about anything dramatic that indicates it’s a mirage of a stat line.

He’s getting fewer strikeouts than we’ve seen him get in his career, but as long as he’s not letting those lost strikeouts turn into extra base hits or walks, you’re not going to be too worried over half a season. That said, there are some differences in his game that extend beyond the outcomes. First, last season’s velocity decline was not a blip or a glitch. The trend has continued:


In addition, he’s relying on his fastball less often in 2016. Against lefties, he’s added many more sliders and even some changeups. Against righties, he’s added a fewer more curveballs.

zimm 1

This is really evident when you check out his zone profile against lefties. His MO is fastballs up and away and curveballs low, but this year with more breaking balls to lefties, you can see that he’s working a lot lower in the zone.


You can see a similar effect against righties.


It’s not clear if this is a mandate from the Tigers or if it’s simply a feel thing for Zimmermann based on how he likes his stuff. To this point, it’s been effective for him, but if he loses a touch of command and the walks go up or if hitters start squaring him up, he’ll have to revisit he approach to see if he can rediscover his strikeouts.

Zimmermann has mixed in three bad starts among his 15, but overall his been a reliable and steady force in the rotation despite missing time with the groin injury. The drop in strikeouts, and especially the continued loss of velocity is somewhat concerning, but so far he’s shown an ability to pitch effectively in Detroit through his first 15 turns.


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