Sonny Gray's fingers were talking. The right-hander, standing in the visitors' clubhouse at Citi Field, was detailing the essence of his mad science, using its fundamental instruments. 
Gray etched in the air the endless directions a baseball could move -- the world of possibilities into which the variance of finger pressure can breathe life. This is the world of the Yankees' newest rotation linchpin.
"People ask me, 'What are you throwing more of? Are you doing this? Are you doing that?'" Gray said. "You kind of laugh. Because it's just a manipulation of the baseball. It's finger pressure -- gripping the same pitch and spinning it a little different; throwing it a little harder, a little slower. Spin the ball like this, it'll go here; more like this, it'll go here. You can throw a ball that cuts this much, one that cuts this much, one that goes straight, one that goes that way." 
Gray's fingers conjured each invented pitch, tracing the path they'd travel. In 10 days, he would be a Yankee, sent to New York in one of the non-waiver Trade Deadline's most built-up deals. Three days later, Gray would make his Yankees debut with six innings in Cleveland. But here, he was still the A's ace, demonstrating the unceasing tinkering behind his emergence as one of the biggest prizes on the market.

"The best thing about Sonny is he can hold a baseball in his hand and make it do whatever he wants," A's pitching coach Scott Emerson said. "There've been times in games where he's said, 'Oh, I moved the ball over on this finger, because it felt pretty good. And I threw a pitch and it was dirty, and I figured, oh, I'll keep throwing it.' And he throws 25 of those."
Gray throws a four-seamer, two-seamer, changeup, slider and curveball. Each is a genus housing multiple species -- sub-versions of every pitch, thrown with varying finger pressure at varying speeds. It's his way of controlling at-bats and keeping hitters off-balance. This season, Gray's four-seam velocity, as tracked by Statcast™, has ranged from 90.1 mph to 96.2 mph, his two-seamer from 90.3 to 95.8. He's thrown curveballs from 76 to 82.9 mph, sliders from 82.7 to 88.2, changeups from 83.5 to 91.4. 

Gray's philosophy was born at Vanderbilt. In his freshman year, pitching coach Derek Johnson (now with the Brewers) taught Gray the method, emphasizing speed differential within his two-seamer. Johnson had his catchers call three grades of fastball: a "BP fastball," a "fastball" and the "extra fastball."
Gray didn't have five pitch types back then. He didn't even throw a four-seam fastball until pro ball. This was early-stage pitch manipulation, targeting his primary offering. Its scope has since expanded. This season, for example, Gray -- a ground-ball specialist his whole career -- wanted to take fuller advantage of his strikeout stuff. So he started toying with his four-seamer.
"I've probably got more true spin on my four-seam lately," Gray said, cycling his fingers in an inward loop. "That's something I have tried to do."
Gray means straight backspin -- the kind that gets whiffs up, where he's decided to work more, with hitters adopting uppercuts to increase launch angle and aim for homers. In past seasons, he'd emphasized cut and sink, an effort to miss barrels, not bats.
"It's good to be able to beat a hitter to a spot with your fastball," Gray said. "A four-seam with true spin is the best way to get a ball from Point A to Point B -- in any of the quadrants of the strike zone, or out of the zone."
Gray now has one of the highest-spin four-seamers in the Majors, averaging 2,502 rpm according to Statcast™, fourth highest among starters. Last season, it averaged 2,431 rpm. His four-seam whiff rate is 22.2 percent, more than double his 10.7 percent from 2016.

Gray's new spin extends through his repertoire. His curve is averaging 2,899 rpm, sixth highest among starters and up from 2,813 rpm in '16; more curveball spin generates more break. Interestingly, his one pitch to decrease spin is his two-seamer -- and for a two-seamer, low spin induces grounders. Gray's 57-percent ground-ball rate is in the top 10 among starters.
The spin is a symptom of health, a sign Gray is at his creative best. Somewhere between his All-Star 2015 and his arrival in the Bronx as the arm to tie an October rotation together, he temporarily lost that part of himself. He battled through a litany of injuries, leaving him ineffective in 2016 and slow to gain full traction this season. But Gray looks like a front-line starter again. In his past seven outings, he has a 1.59 ERA.
"He's inventing pitches like he has over the course of his time here," Oakland manager Bob Melvin said in late July. "When you've had some injuries, you guard yourself a little as far as letting it go and extending. That's not an issue for him now."
Gray has made another adjustment, too: quieting his mechanics. In his windup, he used to stretch his hands far from his body, raising his leg inside the circle they formed, then flow toward the plate. Now Gray's hands stay tight to his stomach, his leg rising in front of them, and he sits back longer before driving home.

"The plate's 17 inches, and I believe if you keep your body compact inside that 17 inches, your release point will be more consistent," Emerson said. "You'll be on the plate more."
Gray's release is more tightly-concentrated, providing a uniform origin point from which his myriad pitches and their unique iterations can diverge. Gray still thinks in Johnson's old terms -- BP, regular and extra. Only now they're not contained to his fastball.
"It's with all my different pitches," Gray said. "You can throw a curveball 76; the very next one, 81. I might throw a changeup 85, I might throw one 91. In my brain, it's the same pitch. To a computer or person that doesn't understand what I'm going about, one might be a 'sinker,' one might be a 'changeup.' But to me, it's the same grip, same everything, with a tiny manipulation and different speed."

The topic invariably arises in conversation with other pitchers. ("We talk pitching; that's what pitchers do," Gray said.) Even within the pitching cabal, Gray's amorphous repertoire and ever-changing speeds sometimes seem occult. They are what make Gray Gray.
"Some people cannot do that to save their life," Gray said. "But I can't do what other guys do. Some guys throw an 80-mph really, really good changeup, and their fastball's 94, and I don't have a clue how they do it. They try to explain it. I try to do it. I can't.
"I can't throw a 70-mph curveball. They can't throw a changeup 90 and also 85. But all pitchers are different. That's what's cool about it."