NBA

Knicks, fans should embrace the playoff nerves

BOSTON — You would think the butterflies go away, but they never do. Not now. Not in the run-up to the most important basketball games of the year.

Today Chauncey Billups will play in his 140th career NBA playoff game. He already has played more than a season-and-a-half of these high-octane, high-viscosity games. He has won 77 of them. He has a Finals MVP trophy in his collection, and came awfully close to adding a bookend. If anyone should take what’s coming in stride, it’s Billups. They playoffs should fit him as comfortably as a smoking jacket and slippers.

“Nah, man,” he said yesterday, smiling after the Knicks went through their final practice at their headquarters in Westchester before heading east toward Boston. “When the stakes are on the table, when the games mean the most, I don’t care how many times you’ve been through it, you still feel nervous. You still feel it in your stomach. It’s a good feeling. I know even those guys have it, as many games as they’ve played like this.”

CONFIDENT KNICKS GEARED TO UPSET CELTICS

LANDRY FIELDS’ PLAYOFF DIARY: FIGHTING OFF THE JITTERS AS TIP-OFF GETS CLOSER

SERBY’S SUNDAY Q&A WITH…CARMELO ANTHONY

PHOTOS: COURTSIDE REGULARS

You know what Billups is talking about because you have waited seven years to see the Knicks in the playoffs. You have waited almost 10 full years to see the Knicks actually win a postseason game. It’s been so long since you’ve been entitled to feel this way that it probably seems foreign. Who gets nervous before a basketball game?

Billups does. Amar’e Stoudemire and Carmelo Anthony do. Billups is right: Even though the Celtics have played as deep as anyone the last three seasons, you know they’re feeling it. Hell, Bill Russell won 11 championships in 13 years in this city back in the day, and he was never completely ready to take care of business on the floor until he first got sick in the locker room.

KNICKS-CELTICS PREVIEW

BERMAN’S SERIES PREVIEW

COMPLETE KNICKS COVERAGE

Yeah. Embrace the butterflies. Embrace your nerves. It’s a good thing.

“I think if you aren’t nervous, it means you don’t think you have any shot to do anything special,” Knicks coach Mike D’Antoni said. “And I think everyone one of us believes that we’re capable of doing some terrific things here.”

Why shouldn’t they? And why shouldn’t you? Are the Knicks significant underdogs heading into this series? Of course they are. Have they sometimes looked like a pickup team thrown together five minutes before the layup line since The Trade, even on nights, like this one, when they’ve been at full strength? You bet.

Can you really expect the Knicks to shock the Celtics?

No, you can’t expect that, unless you have custom-fitted orange-and-blue blinders. But you can hope. You can look at the fact that the Pacers, who finished 25 games behind the Bulls in the Central Division, walked into Chicago and gave the team with the league’s best record a serious scare. You can look at how Philadelphia jumped over the South Beach talent early in that game. You can remember 1990, the last time an aging Celtics team with championship pedigree was fixing to bury an overmatched Knicks team, try to remember how that turned out.

“It’s the playoffs, man,” Anthony said. “We’ve seen it time and again through the years. Anything can happen.”

So that is what the Knicks will pursue starting tonight at TD Garden: anything. And maybe a small piece of everything. The irony is that the last time the Knicks were playoff regulars, they almost always were carrying the favorite’s burden with them. Back in ‘01, it shocked the city when Toronto rallied to oust them in Game 5 at the Garden, ushering in a decade of despicability.

Now? If they aren’t yet playing with the house’s money, they’re playing without any cloak of expectation. Even most of their clear-eyed fans think the Knicks will have a hell of a time figuring out the Celtics. What’s to lose?

Perhaps the better thing to ponder is this: Think of how much there is to gain.

michael.vaccaro@nypost.com