The Mets won’t get an opportunity to see their former prospect in person until early August, when they travel to Detroit. If Michael Fulmer is still running a scoreless innings streak by then, we’ll really have a story. For now, we have a neat anecdote, and an encouraging start to a career.

Fulmer, the Tigers’ rookie right-hander traded by the Mets in exchange for Yoenis Cespedes last year, hasn’t allowed a run in 28.1 innings. It’s a stretch of starts that’s gotten him compared (fairly or not*) to Jake Arrieta just nine games into his career. It’s a stretch of starts worthy of consideration, especially given Fulmer’s first four were nothing short of a disaster. Is the real Fulmer closer to those first four, closer to these recent five, or somewhere in between? What changed?

*Not.

Much has been made of the changeup. Manager Brad Ausmus even went so far as declare a sort of pitch-type ultimatum regarding the changeup and Fulmer’s long-term future as a starting pitcher in the big leagues.

From a piece by Catherine Slonksnis of Bless You Boys:

“It’s going to be enormous for him,” manager Brad Ausmus said after the game. “As a starter, if he’s going to be a starting pitcher longterm, I think the changeup or some other pitch like it is going to be very important for him against left-handed hitters.”

Fulmer’s held up his end of the deal. A two-pitch guy in the minors, Fulmer had always gotten by on just his fastball and slider. The Tigers wanted more changeups, and they got more changeups:

The red line marks the start of Fulmer’s dominance. To the left of the red line: 7% changeups, 6.52 ERA. To the right of the red line: 18% changeups, 0.26 ERA. It’d be silly to think the changeup’s been responsible for the entire emergence, but it’s certainly played a role. Fulmer said something “just clicked.” Now, it’s served as a legitimate out pitch. The 40% whiff rate is well above average for a starting pitcher. He’s trusting it against right-handed batters on the first pitch, with two strikes, and everywhere in between. The location’s improved the more he’s thrown it:

And then there’s this. You remember Jeff Sullivan’s pitch-comp exercise? It’s mostly just for fun, but I wanted to have some fun with Fulmer’s changeup, so I pulled this trick out of the bag. Mostly I was just curious, but when the numbers showed up the way they did, I couldn’t not post them:

The Closest Changeups to Michael Fulmer’s Player Velo H Mov V Mov Spin Michael Fulmer 86.6 7.1 1.9 1772 Felix Hernandez 87.5 7.4 0.8 1825 Zack Greinke 88.8 7.1 2.8 1749 Chris Archer 87.6 7.2 3.7 1795 Corey Kluber 86.3 6.6 3.2 1684 AVERAGE 87.4 7.1 2.5 1765

The first two names are the names that really matter, because the first two names have reputations as two of the best changeup-throwers in baseball. Of course, there’s a major limitation here, and that’s that Felix and Greinke’s changeups are so good because of how they play off the respective fastballs. Felix and Greinke both throw in the low 90s, making their hard changeups resemble their fastballs almost to a T. This is what makes them so effective, not necessarily the movement. Greinke worked for years to get as little velocity separation as possible. Fulmer’s got a 10-mph gap. But he also gets as much arm-side run on the change as Felix and Greinke! And he gets as much drop!

He’s also got a fastball that shares movement traits with Greinke. The fastball goes 96 on average — one of the 10 hardest thrown four-seamers in baseball this year. But where it really sticks out is its “rise” — 10 inches more than a ball thrown without spin.

It’s the same kind of rise Greinke’s four-seamer gets. It’s the same kind of movement in general that Greinke’s four-seamer gets, just with an additional 5 mph of life:

Four-seam fastball movement characteristics

Fulmer : 1.3″ horizontal, 10.5″ vertical, 2,343 RPM

: 1.3″ horizontal, 10.5″ vertical, 2,343 RPM Greinke: 1.6″ horizontal, 10.1″ vertical, 2,397 RPM

This actually makes our Greinke changeup comp from earlier look a little better. The velocity may be off — and the velocity may be the most important factor to the success of Greinke’s changeup — but at least they share the same movement separation between their fastball and changeup. All that separates the two is a velocity gap of about 7 mph. That’s not bad for a pitch that Fulmer didn’t trust to throw against same-handed batters just a couple weeks back.

And of course, this is to say nothing of his slider, another pitch getting above-average whiff rates, the pitch that’s been his true out pitch all along. To say little of the fastball with excellent rise that Fulmer wisely elevates in the zone about two-thirds of time, one of the highest rates in baseball this season and right on par with his teammate Justin Verlander, who throws a similarly high-rising heater. The changeup was just the side project, the pitch that needed to come along eventually. It might already be here.

Fulmer thus far has actually been better against lefties than he’s been against righties. He’s held lefties to a wOBA of just .243, while a handful of home runs to righties have his wOBA against same-handed batters at .302. That won’t last forever, of course, but for a guy with the kind of fastball/slider combination that Fulmer possesses, the right-handers shouldn’t be a problem. The challenge that Fulmer had been issued was to throw a good enough changeup to keep left-handed hitters at bay. Thus far, he’s showing that challenge to be one he can handle.