Just over three years ago (November of 2015), the Tigers announced that they had signed FA RHP Jordan Zimmermann to a 5 year deal worth a hefty $110 million.
Detroit had been looking to sign a #2/3 SP to pair with JV. From 2010-15, Jordan Zimmermann was just that, producing anywhere from 3.0 WAR to 5.3 WAR. That consistent and impressive level of production warranted a large pay check, which the Tigers were willing to dish out. The primary reason I was concerned at the time of the signing was his declining fastball velocity, which resulted in fewer whiffs…
2014: 94.5 MPH / 8.2%
2015: 93.7 MPH / 5.6%
Handing out a huge contract like that to a guy whose velo is already starting to drop as a 29-year-old could be perceived as a mighty gamble.
Zimmermann’s WAR in his first three seasons with the Tigers totaled 3.2. In his final season with the Nats, he was worth virtually the same (3.0 WAR). The Tigers are paying him to pitch like a #2/3 SP, but his statline resembles that of a backend starter. The dwindling FB velocity trend has unfortunately continued…
2016: 92.5 MPH / 5.1%
2017: 92.2 MPH / 5.5%
2018: 91.2 MPH / 3.7%
While age seems to be taking a hold of him, there is rebound potential. This past season, Zimm’s offspeed pitches all generated a high percentage of swings and misses…
He threw his FB 43% of the time and his changeup 5.5%. If he can throw his changeup more frequently and cut down on his fastball usage, he could potentially become a #3 starter. Hitters slugged off both pitches, hitting for a .315 AVG off the FB and an AVG north of .400 off the CH, which is highly unusual considering the high swing and miss rate on the pitch. Maybe the sample (130 times thrown) is simply not large enough to come to any conclusions (about the effectiveness of his CH).
If he utilized the following pitch mix, here’s what his SwStr% would have theoretically looked like…
2018 pitch mix
Proposed pitch mix
Estimated Overall SwStr% with improved pitch mix: [2018 total pitches – 2073; 25% fastballs – 518 pitches; 25% curveballs – 518 pitches; 15% changeups – 311 pitches; 35% sliders – 726 pitches]; [(fastball 3.7 SwStr% in 2018 * 0.25) + (curveball 12.7 SwStr% * 0.25) + (changeup 11.4 SwStr% * 0.15) + (slider 14.7 SwStr% * 0.35)] = 0.925 + 3.175 + 1.71 + 5.145 = 11.0 SwStr%
In November, 2018, Zimmermann underwent successful core muscle repair surgery. Hopefully, he remains healthy and transforms into the pitcher the Tigers first envisioned when they signed him.
If Zimm can develop more of a feel for his changeup (in terms of not giving up as many hits and HRs as frequently as he did during the season, albeit the small sample size) in Spring Training, it could pay big dividends in the regular season.