Yankees right-hander Michael Pineda is having an incredible season. In just 11.1 innings, he’s struck out 17 batters without walking any, a streak that includes — or was caused by, depending on which way you want to point the causal arrow — 6.2 innings of perfect baseball on April 10. A 39.5 percent strikeout rate, even over two starts, is really good, but he’s got another 30 or so starts to make this year. That’s a hot first week from a peripherals standpoint, but J.A. Happ’s done the same thing, more or less, and it hasn’t been that interesting.

But this isn’t a normal pitcher. This is Michael Pineda.

Pineda’s one of those guys who will always be defined by his prospect hype — the 6-foot-7 righty topped out at no. 16 on Baseball America’s prospect list before the 2011 season; Pineda made 28 starts for the Mariners that year, striking out a batter per inning back when that was harder to do and carrying a 3.03 ERA into the All-Star break. By May, Pineda was drawing comparisons to CC Sabathia, and by June, opposing hitters had stopped taking their bats along to face Pineda; instead, they were going to the plate toting a shepherd’s crook, a sling, and a bag of rocks. He tired down the stretch and posted a 5.12 ERA in his last 10 starts, but with Félix Hernández only 25 years old and coming off a Cy Young, the Mariners seemed set at the top of the rotation for years to come.

Related How the Padres Are Pioneering a New Tanking Method

Except, that offseason, Seattle traded Pineda, along with pitcher Vicente Campos, to New York for catcher Jesus Montero and pitcher Hector Noesi. This is my favorite baseball trade at least of the past decade, maybe ever, because players like Pineda and Montero — at the time BA’s no. 6 prospect in all of baseball — never get traded for each other. It was a stunning act of self-confidence on the part of both front offices — “I know your top prospect better than you do” — and it could not have gone worse for either side. Montero moved off catcher to DH and has posted a career .253/.295/.398 slash line, was suspended in 2014 after an ice-cream-related dustup with a scout, and has bounced from Seattle to Toronto to Baltimore since his last big league at-bat in 2015.

Pineda missed all of 2012 and 2013 with an injured throwing shoulder, and in fits and starts over three seasons and change since, has posted a 101 ERA+, but averaged only 24 starts and 138 innings a year. Like Martin Guerre, he went away for a long time, and when he came back, wasn’t the man everyone thought he was. Now 28 years old, Pineda will be a free agent after the season, and he’s still something of an unknown quantity. But since he flashed such brilliance, at such a young age, it’s been hard to stop believing in him.

At this point in his career, Pineda’s an unconventional power pitcher. He still throws fairly hard — his fastball averages a shade under 95 miles an hour and last year topped out at 98.8 — and has a swing-and-miss slider and a changeup. The weird thing about Pineda, however, is that he doesn’t really have a pitch with glove-side break.

Breaking pitches almost always break toward the pitcher’s glove side, which is the source of the platoon effect: a same-handed hitter sees a slider coming in, lines it up, then misses as it breaks away like a string being pulled away from a cat. Pineda’s slider breaks to the glove side, but by only a couple of inches; it breaks almost straight down.

Since coming back from his shoulder problems in 2014, Pineda’s fastball has changed. Brooks Baseball classifies it as a cutter, but PITCHf/x still calls it a fastball. Either way, it breaks arm-side, as does Pineda’s changeup. The combined effect is a slight (about 20 points of OPS) reverse-platoon split: He’s better against lefties than righties.

During his first start of 2017, in Tampa Bay on April 5, the Fox Sports 1 booth threw it down to Ken Rosenthal, who delivered a report on Pineda that included this line: “One of the interesting things about Michael Pineda is that his stats just don’t add up.”

Related How to Lose a Baseball Season in 10 Days

That’s certainly true of Pineda this season. Despite his eye-popping strikeout and walk numbers (his xFIP is 1.20, the best of any starter in baseball as of Friday), Pineda’s ERA stands at 3.97, thanks to a four-run, 3.2-inning performance in that April 5 start. So it looks like Pineda’s had one really good start and one really bad start.

Only that doesn’t tell the whole story, because he got absolutely hosed in his first start. Pineda’s third pitch of the season was an elevated cutter out over the outer half of the plate, and Corey Dickerson chopped it out to left center for a leadoff home run. Since then, Pineda’s given up nine hits, and at least five were cheap. The Rays touched up Pineda for seven more hits in his first game. One was a pop fly off the catwalk at the Trop for a Logan Morrison single. Another would have gotten Pineda out of the second without allowing a run if it hadn’t gone through a gator-chomping Starlin Castro; instead, he went on to give up three runs in the inning. And two more hits were slow rollers that eluded shortstop Ronald Torreyes for reasons that to this day elude me. An inning after Evan Longoria hit a scalding liner for a double to break up Pineda’s perfect game, Morrison homered to the first row of the right-center-field seats, scraping past the wall by a margin so thin it inspired the YES Network booth to invoke the name of Jeffrey Maier.

Pineda’s thrown 164 pitches this year; 31 of them have been swung on and missed, and only two of them have been hit for line drives. He’s pitching closer to his peripherals than his ERA.

To a certain extent, this version of Pineda has always been there. The slider’s always been Pineda’s out pitch (19 of those 31 whiffs have come on sliders), and he’s always thrown a lot of them. What’s new is his use of the changeup, once a distant third in his repertoire; Pineda threw 14 of them (out of 93 pitches) during his perfect game bid — the highest percentage since August 26, 2015. Consequently, Pineda threw only 34 cutters, his lowest fastball/cutter usage rate ever.

It turns out that the changeup might be pretty good, because of how it interacts with the cutter. The arm-side movement on the change is similar to the cutter, though slightly more pronounced, and the changeup comes in around about 5 or 6 miles an hour slower. Pineda threw one past Mallex Smith in his first start that looked like it teleported from one side of Smith’s bat to the other. The catch is Pineda’s changeup doesn’t really have an ideal velocity spread from his cutter. Cole Hamels’s changeup, which is going to end up making him close to $200 million when all’s said and done, comes in about 9 miles an hour slower than his fastball. The pitch Morrison hit out was a changeup that came in at almost 90 miles an hour. But most of the time, it fools hitters into thinking it’s a fastball, which is the point; it’s early, but hitters are whiffing on Pineda’s cutter more in 2017 than they ever have before. If he keeps using it this heavily, the changeup is the legitimate third pitch all good starters need to get by.

We keep believing in prospects like Pineda for so long because it’s hard to accept that what made them great in the first place might not still be there. Maybe, after five years of injury and inconsistency, something’s finally clicked. If Pineda’s the Martin Guerre of baseball, it’s worth remembering how The Return of Martin Guerre ends: The original Martin Guerre shows back up.