Naming Robert Coello’s mystery pitch

As I wrote with some delight a couple of weeks ago, the Angels' Robert Coello is throwing the ancient version of the forkball: forkball grip, but knuckleball movement. He might be the first major leaguer throwing this pitch in many decades. I know a fair bit about the history of the original forkball, but I couldn't find anything interesting about the history of Coello's pitch. And before I could ask him, Jeff Passan beat me to it:

When considering a name for the pitch he rescued from extinction, Los Angeles Angels reliever Robert Coello at first settled on its historic label: a forkball, jammed deep between his index and middle fingers and released, amazingly, with next to no spin, like a knuckleball. Such an incredible pitch, of course, deserves a far greater name, so Coello has settled on the three-letter acronym that ballplayers blurt when he unleashes it.

"The WTF," Coello said. "Catchers call it that. Hitters say it."

--snip--

Whereas other pitchers impart backspin on their splitters and the traditional forkball from masters such as old-style fireman Elroy Face had a tumbling effect, a la curveball, Coello's finds a happy medium: When he throws it right, it doesn't spin at all.

Physicist Alan Nathan, a professor at the University of Illinois who studies baseball and has a particular interest in the knuckleball, hadn't ever seen a pitch like Coello's. His preliminary theory on the pitch: His thumb on the underside of the ball exerts backspin, counteracting the tumbling effect his top fingers put on the ball and balancing the torque so perfectly that the pitch has a knuckleball effect with superior speed (around 80 mph).