When the Washington Nationals traded Robbie Ray to the Detroit Tigers four years ago, in exchange for a then-elite starting pitcher in Doug Fister, Fangraphs' Dave Cameron described the 22-year-old Ray as a "non-elite pitching prospect with some legitimate question marks." A rival big-league executive, quoted by Jayson Stark, called the deal "an epic head-scratcher"—for Detroit. And Bless You Boys, bless them, ran their trade writeup under the headline "Doug Fister Trade is a Terrible Deal for the Tigers."
Four years later, Fister has a 6.75 ERA for the Boston Red Sox. Meanwhile, Ray has a 2.97 ERA for the Arizona Diamondbacks and has allowed less contact than any pitcher in the National League.
This isn't to say that the 2013 analyses were wrong, per se. At the time of the trade, Ray was a non-elite pitching prospect with some legitimate question marks, and it's hard to fault Stark's rival executive, who may or may not have been watching Ray closely at the time, for questioning the deal. Rather, those instant analyses demonstrate a clear and persistent failure of imagination, an unwillingness to project what Ray could become beyond the linear development path he seemed to be on.
There are some player profiles—big body, big-stuff starting pitchers among them—who just seem to take a little longer to find their way in the Major League Baseball than others. That's Ray. After a rocky debut season with the Tigers in 2014 that led to an offseason trade to Arizona, he ditched his heavy reliance on an oft-shaky changeup and went to a clean two-pitch fastball-slider mix, with only the occasional change thrown in there to keep hitters honest. That worked well enough, earning Ray a permanent spot in the Arizona rotation with an exactly league-average 4.32 ERA over 302 solid innings in 2015 and 2016. Last year's improvements in sequencing bumped his strikeout rate up above 25 percent, and that—so you would think—was that. Ray had arrived: not transcendent, but more than good enough.
And then he changed again. This spring, Ray added a curveball. In doing so, he started to resemble another lefty with a big penchant for strikeouts; he started looking like Chris Sale would if Sale was eight inches shorter and, let's be honest, a little bit worse at his job. Ray now throws the curveball about a quarter of the time, almost exclusively down in the zone with two strikes, and it's become an extraordinary weapon in an arsenal that generates—let's run this stat again, because it's also extraordinary—the lowest contact rate in the NL.
Sale is a far better pitcher than Ray has ever been, but comparing the two isn't about results; it's about the look and a little about the pitch mix. Over the last year, Ray's release point has dropped about three inches and migrated nearly a foot farther away from the center of the mound. That's given the 25-year-old lefty a bit more of that side-slinging heat that Sale has so much of. Ray's fastball touches 98 at its max and usually sits around 95, and his slider sits in the mid-80s with tremendous break. Those two alone would be bad enough. The curve allows both to play up in a way that has been extremely unpleasant for NL hitters.
Ray's big frame and inconsistent delivery will continue to hold him back a little bit as he ages into his late twenties. His walk rate will probably always be higher than he or the Diamondbacks would like, but so far in this 2017 season he's found a balance—in his arsenal and in his physical delivery of it—that has resulted in a tremendous number of swing-and-misses from some very talented opposing hitters. The question marks of 2013 have given way to clear statements of progress.
Four years after he was a throwaway in a deal the other team putatively won hands down, Ray has managed to become something close to the best version of himself, a deserving All-Star for a Diamondbacks team on the upswing, 53-39 and in second place in the loaded NL West. It didn't have to be this way. Big lefties with inconsistent results in Double-A don't often turn out to be All-Stars. But Ray has, and in doing so reminds us that progress is not always linear. Sometimes, it's OK to dream about what a prospect might become.