The challenge of a knuckleball, especially the variety that R.A. Dickey has come up with this season, is not only hitting it but catching it as well. Sometimes, it's high. Sometimes, it's low. Sometimes, it's 68 miles per hour. Sometimes, it's 86 miles per hour.

The meandering flight of that unpredictable pitch has confounded many catchers and now that puzzle belongs to Josh Thole and Mike Nickeas of the New York Mets, who share the job of catching Dickey, Major League Baseball's lone knuckleball pitcher.

"It is the hardest thing that has ever been asked of me as a catcher," Nickeas said.

"The challenge is hard to put into words," Thole said. "Every pitch, every inning, every game, there are so many elements that go into it -- the wind, the weather. The pitch is very unpredictable. That's the biggest thing. It's a challenge for everybody, including the umpires."

Dickey threw consecutive one-hitters in June against Tampa Bay and Baltimore, the first one with Nickeas catching, the second with Thole behind the plate. Against Tampa Bay, things went smoothly until the ninth inning when, with a man on first base, two of Dickey's pitches glanced off Nickeas' glove for passed balls, helping the Rays score their only run. The unearned run ended a scoreless stretch of 32 2/3 innings for Dickey.

Both Thole and Nickeas understand that passed balls are an occupational hazard when Dickey's knuckler is dancing its way toward home plate.

"There's nothing you can do to prepare for them," Thole said. "You're going to have passed balls. You'll miss a few. Let that go. It's going to happen. I try to get myself in the same spot to catch the ball. Your stance has got to be the same on every pitch."

After that, Thole takes his chances.

Nickeas prepares for the knuckler by catching as many of Dickey's bullpen and side throwing sessions as he can.

"That way, I can see the way the ball moves," he said. "The more I catch him, the more comfortable I am. I know what it does, but catching it is an entirely different experience."

Knuckleball pitchers have their own private community and talk all the time. One of Dickey's closest friends in baseball is Tim Wakefield, a knuckleballer who retired this season. When Thole was having trouble catching the pitch last season, Dickey asked Wakefield to hook the catcher up with Doug Mirabelli, who was Wakefield's private catcher in Boston and something of an expert on catching the pitch. Mirabelli led the American League twice in passed balls and had 74 of them in a 12-year career, all but six of them trying to catch Wakefield.

Mirabelli was up front with the Mets' catcher.

"He told me to understand you're going to lead the league in passed balls," Thole said.

Mirabelli was right about that. Thole had 16 of them last season, tops among National League catchers.

Nickeas said he welcomed the challenge Dickey's mind-of-its-own knuckler presents.

"I'm one of just a handful of catchers who know what it's like," he said. "That's pretty cool. If you miss one, you put it away. It's tough, but it's become more fun."

The Mets catchers use an oversized mitt when Dickey is pitching.

"It's a women's softball catcher's mitt," Thole said.

With its deep pocket, that would seem to pose a problem getting the ball quickly enough on attempted stolen bases but Thole said that's not the case.

"R.A. is so quick to the plate and holds runners so well that he gives you the best chance to throw out runners," he said.

Thole has improved defensively this season after extensive work last winter with the Mets Minor League catching coordinator, Bob Natal. Still, the challenge Dickey presents can be a daunting one for a catcher accustomed to catching conventional pitchers.

"Every five days, you know you'll have your hands full," he said. "We have fun with it."

Hal Bock is a freelance writer based in New York.