How do you catch a knuckleball? is a question that has baffled major league backstops for decades. Wise old Bob Uecker seemed to have the best philosophy: “Wait until it stops rolling and then pick it up.”

The most enigmatic of pitches, the knuckleball is one of baseball’s great lost arts. Even when it’s working best, the pitcher really has no idea where it’s going. It darts, it flutters, it sinks. It taunts a hitter — just sitting there begging to be smashed, and then it’s gone again. Though it’s always been a rare pitch mastered by only a handful of hurlers, it practically disappeared from the game once stadiums installed radar guns and began flashing the speed after every pitch. (Knuckleballs barely break the speed limit.) With Tim Wakefield of the Red Sox (above) retiring, R.A. Dickey of the Mets is the lone oddball pitcher is still flicking the knuckler. The two right-handers are featured in a new documentary about the pitch that will premiere at the Tribeca Film Festival on April 21.

Take a look at a short teaser for Knuckleball!.

Before Knuckleball!‘s world premiere at the free Tribeca Drive-in on April 21, fans can attend pitching clinics with Dickey and Wakefield, as well as famed knucklers Charlie Hough and Jim Bouton. The outdoor festivities begin at 6:30 pm.

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