It isn't going too far to say that Michael Fulmer has rescued the Detroit Tigers' season. Imagine the first half without him and you'll find yourself holding a trade deadline firesale in your head. Fulmer is the standout Rookie of the Year candidate in the American League so far, and he has dominated opponents with amazing poise and consistency. For the Tigers to force their way into the playoffs, Fulmer's second half contributions are going to be a major key, even with a looming limit on his innings.
The good news is that Fulmer's profile doesn't belie any major corrections coming. Fulmer ranks 8th in the American League with a 3.53 FIP this season. His league-leading 2.11 ERA for starters with 70 or more innings isn't going to hold up entirely, but there's reason to think he can continue to outpace his peripherals.
So far this season, Fulmer has run a .252 batting average on balls in play (BABIP). He's moderated the hard contact, but it typically takes a high ratio of fly balls and pop-ups to sustain a BABIP below .300. Fulmer is a distinct ground ball pitcher, which helps him to limit the extra base power, but also means more hits overall.
Where those ground balls may turn back in Fulmer's favor is in maintaining a higher-than-average ability to strand runners on base. With the Tigers' infield being one of most adept in baseball at turning double plays, Fulmer will have help erasing an extra baserunner here and there. With almost half the balls in play against him coming on the ground, he should also be successful at maintaining an xFIP-defying home run rate.
One concern you have to have with Fulmer is whether the league is going to adjust now that a lot of teams have had a crack at him. So far, only the Tampa Bay Rays and Cleveland Indians have faced Fulmer more than once. On the positive side, both lineups were thoroughly dominated the second time despite being more familiar with Fulmer's stuff and delivery. Having a lot more film on him didn't help them a bit.
Maybe the best indicator that familiarity doesn't help too much is Fulmer's whiff rate, which has stayed very stable throughout the first half. Interestingly, as Fulmer's slider has faded a little bit in effectiveness, his changeup has been spectacular. It's pretty incredible for a pitch no one expected major progress from this season.
Signs point to Fulmer having no major correction in his future. His changeup and slider are excellent and complement each other beautifully. Despite both types of fastballs being relatively straight, with no actual sinking action, hitters continue to struggle to drive the ball in the air. Fulmer hides the ball well with a bit of a cross-fire stride, and again and again, his already elite velocity seems to play up against live hitters.
The only real question is how much the Tigers will let him pitch this season. Fulmer is at 76 2/3 major league innings currently, and has thrown another 15 1/3 frames in the minors. The team has suggested that they'd prefer to keep him to 155 or so innings this season. That leaves roughly 80 innings remaining for him. Fulmer could make his remaining 14 starts, assuming six innings per outing, and come in right around 160 innings. The Tigers would then face the unenviable task of shutting their brilliant rookie down right as the playoffs begin, should they earn the right to play in October.
Obviously, asking him to throw 200 innings is madness. That's rare territory in this era, even for veteran starting pitchers. Still, it's not out of the question that Fulmer could continue to pitch in the postseason should the opportunity arise. If the Tigers skip him twice and limit his pitch count per outing, they should be able to get through September with Fulmer close to 150 innings. At that point, how he feels and how he's throwing the ball should dictate whether the Tigers can allow him to start games in October.
Right now, Fulmer is pitching as well as anyone in baseball not named Clayton Kershaw. Fulmer's peripheral numbers support the idea that he will be able to maintain that success going forward. The Tigers will have a tough call figuring out how to get to the postseason while managing to rest Fulmer enough to still be able to use him at that point. One could argue that they need all the innings Fulmer can muster just to get there. However many innings the Tigers ask from him, at least all signs indicate they'll continue to be good ones.