Heading into the 2016 season, many considered the Detroit Tigers’ biggest weakness to be their starting rotation. Justin Verlander and Jordan Zimmermann were going to make a decent one-two punch at the top — remember, national pundits didn’t even trust Verlander all that much — but there would be a steep drop-off after that. One month into the season, all of those fears (even the ones about Verlander) were being realized.
Over the course of the next five months, the Tigers’ rotation became one of their biggest strengths. Rookie Michael Fulmer evolved into one of the best starters in the American League. Daniel Norris stayed healthy and reminded people why he was even more highly regarded than Fulmer as a prospect. Matt Boyd turned some heads with a solid performance, though his last outing of the year spoiled his overall numbers a bit. Verlander shook off his April struggles and turned in a Cy Young-caliber season.
Thanks to these performances, the Tigers’ rotation finished the year with a 4.25 ERA, tied for the fourth-lowest in the American League. Their 4.31 FIP ranked sixth in the AL, while a 4.30 SIERA put them seventh. They compiled 12.6 wins above replacement, according to FanGraphs, which put them fifth in the AL. Strikeout rate, walk rate, you name it. In just about every important statistical category, the Tigers’ rotation ranked above the league average.
This may not seem all that impressive given the players listed above. However, the Tigers also had to endure 48 starts from Anibal Sanchez and Mike Pelfrey, both of whom ranked below league average in most categories. Both pitchers posted ERAs and FIPs above 5.00 in their starts, well above the league average of 4.42. Sanchez just barely managed to post an above average strikeout rate, at 20.4 percent. However, Pelfrey’s abysmal 9.9 percent strikeout rate was roughly half of the league average of 19.9 percent. Pelfrey limited home runs better than the average AL starter, but Sanchez’s 1.82 homers allowed per nine innings was one of the highest rates in the league.
Jordan Zimmermann was also a statistical anchor by season’s end. His 14.2 percent strikeout rate was well below the league average, while his 4.93 ERA was over half a run higher than the average AL starter. His 4.53 FIP was also worse than league average, though not by as large of a margin. Zimmermann’s walk and home run rates were both better than average, but those don’t outweigh how poorly he performed in other areas. Even his 1.37 WHIP was slightly above the league average of 1.34. Given what was expected of Zimmermann and how dominant he was to start the year, seeing his numbers fall off this much was a major disappointment.
On the positive end of the spectrum, we have Justin Verlander. The should-be Cy Young winner led the AL in both versions of WAR, and his 3.04 ERA was second only to Toronto’s Aaron Sanchez. Verlander was first in strikeout rate, first in K-BB%, second in innings pitched, and he posted the lowest WHIP and batting average allowed of any qualified AL starter. His 3.48 FIP ranked a distant fourth to Cleveland’s Corey Kluber, but that is entirely due to a home run rate of 1.19 per nine innings, which was the 18th-highest among 39 qualified AL starters.
Michael Fulmer did not end up pitching enough innings to qualify for the ERA title, but his numbers match up with just about any starter in the AL. His 3.06 ERA ranked third among AL starters (minimum of 150 innings pitched). His 1.12 WHIP was seventh in the AL, while his 3.71 FIP was 11th among AL starters. He accumulated 3.0 fWAR, which tied him for 15th in the league despite not qualifying for the ERA title. On a per-inning basis — Fulmer ranked 41st in the AL with 159 innings pitched — he was as effective as any starter in the league.
Daniel Norris and Matt Boyd didn’t crack any league-wide leaderboards, but they posted above average numbers in many categories. Both pitchers managed strikeout and walk rates better than the league averages of 19.9 and 7.6 percent, respectively. Norris’ 3.42 ERA was a full run better than the AL average, while Boyd’s 4.81 ERA as a starter looked a lot better before his rough outing against the Kansas City Royals on September 25. Norris also posted a better-than-average 3.89 FIP, while Boyd’s elevated home run rate pushed his 4.78 FIP above the league average of 4.42. Both pitchers managed healthy a K-BB% as well; Norris’ 16.8 K-BB% would have ranked ninth in the AL had he pitched enough innings, while Boyd’s 13.8 K-BB% would have tied him with Toronto’s Marco Estrada at 18th in the league.
The Tigers’ rotation will still pose some question marks as they head toward 2017, assuming they maintain the status quo this offseason. Zimmermann will need to bounce back from his rough year, while Verlander will need to continue to stave off Father Time. The Tigers’ young pitchers will need to ward off some regression, and in Norris’ and Boyd’s cases, prove that they can sustain these numbers over a full season. Anibal Sanchez and Mike Pelfrey will need to contribute in some fashion as well. However, after a strong 2016 season, these worries are nowhere near as big as they were a year ago.