Before Michael Fulmer returns from the disabled list on Friday to face the Chicago White Sox in his first start since July 14th, it’s worth considering the peculiar position he and the Detroit Tigers are in relation one another. For over a year now, there have been quiet trade rumors following the big right-hander but nothing that seemed close to a deal. All parties involved want to see Fulmer progress into the frontline starter he’s capable of becoming, but the Tigers also have ulterior motives. Rather than build a new rotation around him, they may well opt to trade him in the right deal. The rub, of course, is that should Fulmer emerge as a legitimate ace, it will suddenly be a lot more painful to contemplate trading him.
To get to that fork in the road, the Tigers need a breakout from Fulmer. They can’t afford to trade him away in a fairly tough market unless they come away without franchise changing talent. They need to trade him at his peak value, and after a very mediocre 2018 season thus far, he’s potentially a long way from that point. The other option is to make him part of their long-term plans. The worst case scenario would be selling low on him and then watching him blossom into an ace for another organization. As a comparison, I offer you none other than his last opponent before hitting the disabled list, the Houston Astros’ Gerrit Cole.
As recently as last season, Cole was in a similar place in his career to the one Fulmer finds himself in right now. Cole is two years older, and hit the scene even harder than Fulmer did, giving the Pittsburgh Pirates two good abbreviated seasons in 2013-2014, before erupting with a brilliant 2015 season put him in the conversation among the best pitchers in the National League. But Cole’s next two seasons were muted, and while he was still a good starting pitcher, doubts emerged as to whether he could recapture his earlier form. His strikeout totals were pedestrian, and his future with the Pirates was in murky territory.
Like Fulmer, Cole’s past success, age, and power stuff hinted that more was possible, but when the Astros traded for Cole this past offseason, they weren’t really paying for an ace. Yet with a few adjustments, they’ve gotten one just the same. Just in the past calendar year alone, several Tigers pitchers have moved on to new teams and seemingly stepped up their game overnight, as Cole did. That can’t happen with Michael Fulmer.
The high heater
Fulmer and Cole are 6’3 and 6’4 respectively, both weighing in over 200 pounds. They’re prototypical big, right-handed power pitchers who can sustain mid-90s heat on their fastballs deep into an outing, and have the ability to reach back for 98-99 mph when they want it. There are some mechanical differences, but the two pitchers have a lot of similarities in size and in stuff. Both typically throw sliders and changeups that are harder than average — though Fulmer tried taking some off his slider this year, to no positive effect. And, until 2018, each threw a fairly balanced mix of fourseam and twoseam fastballs.
The premise here is fairly simple and reflects a growing trend toward combating flyball hitters and uppercut swings by pitching at the top of the zone more often. Throw more high fourseamers. Prior to the start of the 2018 season, the Astros convinced Cole to ditch his sinker almost entirely, and tailor his sequencing around the fourseamer instead. The result has been an enormous spike in his swinging strike rates and the highest strikeout rates of his career. Cole managed to move to the American League and raise his strikeout rate from 23.1 percent to 34.7 percent seemingly overnight.
Cole is throwing basically the same ratio of strikes and first pitch strikes, so he’s not throwing more bait pitches to get all these strikeouts. He’s basically abandoned his changeup in favor of a slight increase in breaking ball usage, but otherwise the total commitment to the fourseam fastball is the only notable change. Like Charlie Morton before him, Cole went from a sinker-heavy approach under Pirates’ pitching coach Ray Searage, to throwing more fourseamers up in the zone with the Astros. Both teams are analytically minded, but the Astros unlocked something the Pirates could not. Fulmer’s arsenal is different than Morton or Cole’s, but it seems likely that he could benefit by following their example.
Fulmer and the fourseamer
This isn’t to say that simply throwing more fourseam fastballs will necessarily transform Fulmer into a Cy Young contender. However it’s notable that his wOBA allowed is just .273 on the fourseamer this season, with an isolated power (ISO) of just .080 against the pitch. This in a season in which Fulmer is allowing the worst home run rate of his career. By comparison, against his sinker, hitters have posted a .339 wOBA and an ISO of .112. Yet Fulmer is throwing the sinker 35 percent of the time this season, versus 25 percent for the fourseamer. Against both right and left-handed hitters, Fulmer relies on more sinkers as a percentage of fastballs than he does fourseamers. It might be a good time to mix that up, especially with runners on base.
A pattern this season has seen Fulmer dominate many of his starts, only to erupt for a single bad inning. As men reach base, and then move into scoring position, Fulmer’s strikeout rate slips, his sinker usage increases, and as a result, his groundball percentage increases as well. Perhaps in turning to the sinker to get groundballs, and hopefully, double-plays, with runners on base, he’s getting too predictable. Particularly if he doesn’t have good feel for his secondaries. Maybe, using the pitch that’s been more effective, more often, would kickstart his season and help him to get pop-ups and punchouts in key situations.
It’s hard to ignore the fact that Fulmer leaned on the fourseam fastball much more during his Rookie of the Year campaign in 2016.
We also have evidence in favor of the fourseamer by looking at current whiff rates on the pitch. By using it more, and more often up in the zone, Cole increased his whiff percentage on the fourseamer from nine percent in 2017, to 14 percent this season, powering part of his increase in strikeouts. Fulmer already holds a 13.7 whiff rate on the fourseamer in 2018, and that’s a drastic improvement over the sub-nine percent numbers he posted his first two seasons. Meanwhile, the whiff rate on his sinker sits at 5.3 percent. At least part of the extra strikeouts Fulmer needs to consistently dominate might be there for the taking.
There are also reasons why the high fourseamer may not work as well for Fulmer as it did for Cole. While they each throw the pitch with high-end velocity, Fulmer lags behind Cole in terms of spin rate. Whereas Cole averages 2349 rpms on his fastball, Fulmer checks in at a pedestrian 2256 rpms. That’s not a huge difference, as Cole’s spin rate is above average but nowhere near elite, but it’s enough that switching to a heavy dose of fourseamers may not be as effective for Fulmer as it was for Cole. However, we can take some comfort from the fact that the same change has worked wonders for Charlie Morton, and Morton’s fourseam spin rate lines up almost exactly with Fulmer’s.
Another notable point is that despite Cole’s somewhat higher spin rate, Fulmer throws from a higher release point, enabling him to get just as much rising action as Cole does. Cole’s fourseamer “rises” 9.69 inches this season, according to Brooks Baseball. Fulmer’s fourseamer “rises” 9.42 inches. That’s an insignificant difference in movement, and it speaks to the potential for this change to help Fulmer too, despite neither having the 2500+ rpms of the elite guys like Justin Verlander. You don’t necessarily need elite spin rate to pitch up in the zone when you’re pumping 95+ mph.
The other issue one has to consider, is the fact that Fulmer doesn’t throw a curveball. The change in fastball usage alone has paid dividends for Cole and Morton. However, the high fastball typically pairs better with curveballs because they start out on the same eyeline. For example, Jeff Sullivan at FanGraphs wrote a nice piece about some of the adjustments the Oakland A’s have made with Mike Fiers since acquiring him, and it falls along these lines as well. Fulmer doesn’t throw one, and it’s hard to say if his slider and changeup would pair better with the fourseamer or not. What seems well worth exploring, is whether or not the fourseamer is just a better pitch to lean on than his power sinker.
Obviously throwing more high fourseamers isn’t a panacea. Fulmer’s command has been inconsistent at times this year, and he still needs to improve his slider, and rediscover the feel for the changeup that made it such a weapon in his 2016 Rookie of the Year campaign. Fulmer told Max Bultman at the Athletic recently that he was very pleased with some of the work he’d accomplished working on his slider and fastball during his rehab assignment.
Now that I had the 2-3 weeks in Lakeland to work on that full time, coming back here and finally throwing in front of (pitching coach Rick Anderson) again, he was shocked too. That was good. I was happy I could show him that I’ve been working on some stuff.”
Whether Fulmer has a Gerrit Cole-like breakout available to him is an open question. But you can bet that teams who believe he does will be trying to pry him from the Tigers on the cheap this offseason. The Tigers need to make that transformation happen here in Detroit, or they’re liable to lose a trade by accepting a deal for the pitcher Fulmer currently is, instead of the pitcher he may yet become.