Pass-to-run.

For Andy Reid and his playoff-bound Eagles, the phrase refers not so much to a ratio as to a rationale.

As the 2008 regular season proved yet again, Reid was not born to run. In fact by now, 10 years into his Philadelphia tenure, the Eagles coach's pass-first philosophy is as deeply embedded a character trait as his reticence.

Throughout this seesaw Eagles season, which so unexpectedly will continue Sunday in Minneapolis against the run-driven Vikings in a wild-card playoff meeting, Reid's penchant for the pass has been a dominant theme among disgruntled fans, frustrated reporters, and, at times, even the players in his own locker room.

It was the lightning rod attracting the spark of his sharpest critics, and typically the first reason cited by all those who would like to see Reid - you should pardon the expression - run out of town.

Run-first teams win Super Bowls, the coach's detractors liked to point out, referencing the 2007 Giants but conveniently forgetting the 2006 Colts. Brian Westbrook needs more carries, they screamed, noting the running back's per-carry average while overlooking his fragile health.

To be sure, there can be little argument about the Eagles' tendencies. They are hopelessly addicted to the pass. While the average NFL pass-run ratio was 55-45, the Eagles threw the ball better than 60 percent of the time. And only Arizona, Indianapolis, Detroit, Cincinnati, New Orleans and San Francisco ran for fewer yards per game.

But, as Reid's defenders countered, of the six NFL teams to throw better than 60 percent of the time this season - the Eagles, Cardinals, Broncos, Colts, Lions and Saints - half made the playoffs.

So the eternal conundrum remains: Pass or run?

There's likely no satisfactory answer to football's version of the chicken-or-egg question, even if statistical geeks at the Advanced NFL Stats Web site did develop a means to try to resolve it:

"The optimal run/pass ratio is found by taking the derivative of the utility function and setting it equal to zero, thereby finding the curve's maximum," it was explained. "Each team's optimum run/pass ratio is based on the relative strength and variance of their running and passing games."

If that sounds complicated, consider the response from Mark Cuban, the bad boy owner of the NBA's Dallas Mavericks, when he was asked whether he thought the Eagles ought to do a better job mixing the pass and run.

"You should do whatever you think will win you games," Cuban, who watched another Dallas pro team, the Cowboys, get blown out by the Eagles on Sunday, said in an e-mail reply. "I'm guessing they are doing what they think is the right thing to do. Unless they, of course, are trying to gain the element of surprise, which could work, unless the other team thinks the other team might be using the element of surprise and try to be surprising themselves, which, of course, just returns them right back to where the numbers said they would be."

From those with better wardrobes - if not bank accounts - came more decipherable views on the Eagles' lopsided proclivities.

Cris Collinsworth, the NBC/NFL Network commentator and ex-wide receiver, said what mattered most for the 9-6-1 Eagles wasn't how many times they threw the ball but how many times they (a) got it in Westbrook's hands and (b) how Donovan McNabb ran.

"If Brian Westbrook runs it 15 times and catches seven, eight passes, touches it 22 or 23 times, they're in good shape," Collinsworth said yesterday. "I don't care if it's a screen or a flare or how you get the ball in his hands. That doesn't make any difference to me. I just think that he's a special guy.

"The other part of it, I think, is that Donovan McNabb take off and run once in a while. . . . Defensive coordinators playing the Eagles would all say the same thing: 'I think we can play these guys all right. But one thing we cannot handle is when Donovan takes off and runs.'

"If those two parts of the equation come into play, it doesn't make any difference to me if they're throwing the ball 65 percent of the time or not. If they find ways to get those two elements involved, then I think their offense can be tremendous," Collinsworth said.

John Madden, a Super Bowl-winning coach and another NBC commentator, said Reid's pass-first philosophy wasn't what got the Eagles in trouble at times this season. Instead, he said, it was their play-calling.

"You have to have a balance, whatever that might be," said Madden. "But there are some play-callers, and I've seen this all my life, that once they start calling passes, they cannot go back to the run. And I think that's what the Eagles fall into sometimes. . . . When you can be critical of them, it's those games when they start to get on those passing streaks, and they just can't get off it."

Reid, of course, this season turned over those play-calling duties to offensive coordinator Marty Mornhinweg. Curiously, Gil Brooks, the man who coached the sons of both Reid and Mornhinweg at perennial power St. Joseph's Prep, suggested it was more important that Philadelphia stick with its philosophy.

"It's like playing those old Central Bucks West teams under Mike Pettine," said Brooks, referring to the high school team that dominated Bucks County football in the 1960s, 1970s and 1980s.

"They weren't known for the pass at all. They'd pound, pound, pound you with the run. But then, just when you'd been lured into bringing nine guys into the box, they'd get a wide receiver open by 20 yards and hit a long pass. That's what they did. They weren't a passing team, but yet the pass was very effective for them. It's probably just the opposite with the Eagles."

For Dan Jenkins, the longtime Sports Illustrated writer and the author of such classic football novels as North Dallas Forty and Semi-Tough, Collinsworth's plea for McNabb to run more was misguided. The NFL, Jenkins noted, is a league long dominated by the star quarterback and the pass.

"How can you pass too much in the NFL?" asked Jenkins. "Would you rather have your quarterback run more and get maimed for life? Sam Baugh brought the passing offense to the pros. It was genius. There weren't enough Bronko Nagurskis to go around. Never will be."

As for Philadelphia's fans, well, their opinions usually depended on the outcome of that week's Eagles game. Lose and they demanded a ground-game commitment. Win and their case of the "run-runs" was cured.

"Even their vaunted passing attack leaves a lot to be desired," wrote a fan whose screen name is FlyEagles midway between the Redskins loss and Cowboys win. "If Westbrook is not 100 percent, there is virtually no run game. The defense is the only thing that is working. What a waste! The Reid mystique is crumbling, but does Lurie have the will to make a change?"

Contact staff writer Frank Fitzpatrick at 215-854-5068 or ffitzpatrick@phillynews.com.