Angels reliever Robert Coello throws a style of forkball unlike any most baseball fans have ever seen. Even catcher Chris Iannetta seemed baffled by it a couple weeks ago:

Take a closer look at the pitch, and how badly it crosses up Iannetta.

That sure looks like a strike, for what it’s worth, but Iannetta’s inability to handle it likely biased the umpire against Coello.

From the center-field camera, there’s nothing terribly exceptional about how Coello’s pitch appears to move. But from the batter’s box, it looks like a knuckleball — wobbling in flight with almost no spin whatsoever.

Here’s a closer look at Coello’s grip. ENHANCE:

Over at Baseball Nation, Rob Neyer has more:

This, my friends, is the original forkball. The forkball we know — a slightly slower split-finger fastball, but still with quite a lot of spin — is not the original forkball. The forkball we know was invented … well, I’ve never been able to figure out exactly when. A few years ago, Bill James and I wrote a book about pitchers. It didn’t sell a million copies, but my mom said she liked it. Anyway, we did an immense amount of research on the forkball, and ultimately I was able to track down a Tacoma Tigers pitcher named Bert Hall, who unveiled an interesting delivery on the 18th of September, 1908. From the next day’s Seattle Times:

The Seattle sluggers could not have hit young Burt Hall yesterday with a canoe paddle. The young fellow simply put the ball between his first two fingers, drew back his arm and let fly. The result was a lot of wiggles on the ball that had the local help completely mystified, and when they hit the ball at all they were so surprised that they sometimes forgot to run.

Greg Cadaret, a left-hander who pitched for eight different teams in the 1980s and 1990s, seems less impressed:

But if Cadaret (and Leary and Perez, for that matter) threw a forkball with some spin on it, then it’s hardly the same pitch Coello’s throwing, no?

Regardless, something seems to be working for Coello so far in 2013. After entering the season with a career 9.00 ERA over 12 innings, the 28-year-old righty has allowed just one run in 10 1/3 innings this season, with 18 strikeouts against only one walk.