New York Mets pitcher R.A. Dickey has done what no other pitcher in the modern era has: thrown two straight complete-game shutouts while allowing just one hit in each game. And he’s done it on the dipping and swerving of one of the rarest pitches in baseball, the knuckleball. Dickey, who bounced around the major and minor leagues for nearly a decade before landing with the Mets in 2010, turned to the pitch as a way to revive his career — and it’s turned him into a superstar. The only active pitcher to use the knuckleball nearly exclusively, Dickey holds an 11-1 record so far this season — the best in Major League Baseball.
What makes a knuckleball so different, so difficult to throw and — the pitcher hopes — so difficult to hit? TIME chatted with LeRoy Alaways, a mechanical engineer at Villanova University who studies the science of pitching.
The difference between a knuckleball and the three other main pitches — the curveball, slider and fastball — comes down to spin. “A typical fastball does 16 to 17 revolutions by the time it gets to home plate,” Alaways says. “The ideal knuckleball, you want to revolve 1.5 to 2.5 times by the time it gets to home plate.” A knuckleball is really almost pushed, rather than thrown, by the pitcher, who holds the ball with his knuckles or fingernails to deaden the spin. The trick is to have the ball’s seams “trip the boundary layer of air,” turning the flow of air around the ball from smooth to turbulent. “As the seams get exposed in random order, the ball dances around randomly,” says Alaways. “It is a finicky pitch.”
But not an impossible one. To find out more about the art of throwing the knuckleball, TIME talked to Tim Wakefield, a former pitcher for the Boston Red Sox and one of the most successful knuckleball pitchers ever to play.
TIME: How did you throw your knuckleball?
WAKEFIELD: I tried to take the spin completely off of it and have it rotate a quarter-turn to a half-turn. I didn’t try to make it spin forward at all. The biggest objective was to take the spin off the ball.
How tough was that to replicate?
There were days where I felt I had too much movement on the ball. In Texas, the wind was always blowing in my face and the ball was moving so much I couldn’t find the strike zone, and I would walk the bases loaded. Pitching inside was ultimate. The ball moved, but it was more controllable than in a brisk wind.
Is it always a fine balance of control vs. movement?
It is a double-edged sword. You want as much movement as possible but also want to throw it in the strike zone. You have to find a happy medium. That is what is so amazing about R.A. He is throwing a lot of strikes. To throw it without any spin and with as much movement and to throw strikes, that is amazing.
What are the mechanics involved?
[Former Texas Rangers knuckleballer] Charlie Hough threw a lot more fluid, the opposite of me. I threw mine with a very stiff wrist. He was very loose and pushed it forward and took spin off it. I had to have my wrist locked, and then it came out without any spin. If I got too floppy, it would spin too much. If you look at Phil [Niekro], [Tom] Candiotti or R.A., the pitch is the same, but the way we got to our release point was a little bit different.
Is it fun to watch R.A. Dickey?
It is, and I’m so happy for him. He is such a great guy, and he’s been through so much. He has definitely paid his dues. I remember when I first met him, when he converted to a knuckleballer with the Texas Rangers. I saw him struggle quite a bit. I saw him give up a lot of homers, which I have done. He has been experimenting a long time, so it is nice to see him getting in his groove.
Has he come to you for advice?
Knuckleball pitching is a very small fraternity. I had the help of Phil, Charlie and Candiotti, and I have been able to pass along information I have learned to R.A. He would call me sometimes on the road and ask what I was thinking about his mechanics. It is nice to be able to bounce ideas off somebody who is doing what you are trying to accomplish. It is a pretty special thing to have that help, and like I said in my retirement speech, I pass the torch to him to keep this legacy and this art of the knuckleball alive.
Why don’t more pitchers try it? Is it just that difficult?
It is not easy, first of all, to be able to have the guile and face the best hitters in the world throwing 65 m.p.h. in hopes of good movement. R.A. throws a bit harder, and I wish I could throw mine as hard has he does. Today’s game is so radar-oriented — they take guys that throw mid-90s to 100 m.p.h. over us every time. But the assets we bring to a pitching staff are vast. We can pitch on short rest because of the lack of strain on our arms. We can pitch in relief in between starts. We can give valuable innings in any role.