There must be something about the nickname Swish that makes it impossible to have postseason success in New York.

Like October-challenged former Yankees outfielder Nick Swisher, the usual Knicks swisher — J.R. Smith — has done nothing to live up to that moniker throughout these playoffs. His constant misfiring continues to be among the biggest reasons the Knicks trail 3-1 in the Eastern Conference semifinals after their 93-82 loss to the Pacers Tuesday night.

“My frustration with myself is extremely high. I take the blame for this whole series,” Smith said after he shot 7-for-22 and finished with 19 points and two rebounds. “It started off in (Game 5) in Boston... I haven’t been playing (like) myself. I haven’t been playing my part.

“I’ve been letting my teammates down. I’ve been letting my coaches down. And it doesn’t feel good.”

Smith, who has played the past two games battling flu-like symptoms, hasn’t had one effective shooting night since he served a one-game suspension for elbowing Jason Terry in Game 3 of the first round against the Celtics.

The NBA’s Sixth Man of the Year is now mired in a 26-for-91(28.6%) shooting slump over his last six games, including 10-for-37 (27%) from three-point range.

“Everybody’s been encouraging me, ‘Keep shooting, keep shooting, keep shooting,’” Smith said. “I’m still trying to get to the basket, trying to get easy ones, easy layups, get to the free-throw line.

“But I’m even missing layups, too. I missed a technical free throw tonight. It’s just frustrating.”