Football always provides an emotional roller coaster. Win one week, and everything’s groovier than a Marcia Brady miniskirt. Lose the next, and the world’s as chaotic as a night on the town with Plaxico Burress.

All of which gives us so much to talk about at the three-quarter pole of New England’s schizophrenic season, but also makes it harder to separate truth from fiction. Are the real Patriots the team that eviscerated the Broncos, 41-7, back in October or the team that melted down at home in a 33-10 loss to Pittsburgh on Sunday?

There’s only one way to find out: drill down into the 2008 season for a little statistical root canal to separate the rotting gums of a flawed team from the solid, shiny enamel of an intriguing club that still has a fighting shot to make some noise over the last month of the season.

Solid: The Age of New England’s Defense

Some pigskin “pundits” would lead you to believe that the Patriots defense is so long in the tooth that it should be clubbed for its tusks and blubber on remote Arctic islands.

The truth is that the Patriots defense is not particularly old – certainly not too old to be effective. The starting unit the Patriots put on the field against the Steelers Sunday averaged about 27.5 years of age and just under six years of NFL experience. Compare that to Pittsburgh’s starting defense – which averaged about 29 years of age and seven years of NFL experience, and included five guys who are already in their 30s.

Yet despite its geriatric age, the Pittsburgh defense has performed fairly well here in 2008. In fact, it’s the leagues best by almost any objective measure.

Pittsburgh’s 30-year-old linebacker James Harrison certainly looked pretty spry as he strip-sacked 26-year-old Matt Cassel on consecutive possessions, didn’t he?

It’s true that two of New England’s more experienced starters, Ty Warren and Adalius Thomas, did not play Sunday. But Pittsburgh’s defense still comes in a shade older when you take those two into account.

So the problem with the Patriots defense is not its age. Nope. The problem with New England’s defense is that it’s not particularly good.

Rotten: The Performance of New England’s Defense

The last time the Patriots defense played this poorly, back in 2002, the team went 9-7 and missed the playoffs. And that was with Tom Brady at quarterback.

The 2008 Patriots surrender 21.2 PPG – which puts them at 12th in the league. So it’s hardly falling apart at the seams. But it’s clearly not up to snuff, at least by the standards of the organization this decade. In terms of points allowed, it’s New England’s worst defense since that 2002 team allowed 21.6 PPG.

I’ve chronicled the futility of New England’s pass defense a couple of times earlier this year. By now, everyone knows that the pass defense is the team’s greatest liability on either side of the ball.

But the run defense isn’t exactly lighting the world on fire, either. In fact, the dirty little statistical secret about the Patriots defense is that it’s not very stout against the run – despite the four No. 1 picks and the trio of savvy, proven linebackers playing in its front seven.

The Patriots surrender 4.06 yards per attempt on the ground – 17th in the NFL this year. The historic average per rush attempt is 4.0 yards – almost every year, the average run offense averages 4.0 YPA and the average run defense allows 4.0 YPA. And the 2008 season is no different.

So what the Patriots have here is (at best) an average, ordinary, run-of-the-mill run defense – no matter how many No. 1 picks and proven veterans they’ve paired in the front seven.

Sure, some will argue that New England’s porous pass defense means the team needs to focus less on stopping the run. That may or may not be true. But the bottom line is that you either get the job done or you don’t. And the Patriots run defense is not an advantage of any kind for this team.

Solid: New England’s Ground Game

Conversely, New England’s running attack has quietly been as productive as any we’ve seen in these parts in a quarter century. It’s a shocking performance considering that the offensive backfield has been decimated by injuries.

The 2008 Patriots average 4.34 yards per attempt every time they run the ball – the team’s most productive ground attack since the 1983 Patriots averaged 4.84 yards per attempt. (The Patriots were one of the best teams ever running the ball in the late 1970s and early 1980s, but organizational ineptitude has marked the franchise’s rushing attack in the years since.)

The 2004 Super Bowl champion Patriots seemed to run teams into the ground each week behind clock-killin’ Corey Dillon. But even those Patriots averaged just 4.07 YPA and 133.4 YPG. The 2008 Patriots average 4.34 YPA and 130.5 YPG, running the ball slightly less often but quite a bit more effectively.

Last year’s Patriots actually ran the ball a micro-fraction better than the champion Patriots of 2004, averaging 4.10 YPA. But the 2007 Patriots had certain strategic advantages over other teams of recent years: they were one of the best passing teams in history, forcing opponents to focus on pass defense.

The 2008 Patriots enjoy no such luxury with Matt Cassel at the helm, which makes the historic productivity of the ground game all the more impressive.

Rotten: Conventional Wisdom

With that said, running the ball well is nice to talk about and makes fans feel good. But it doesn’t really help you win football games, despite the fact that conventional gridiron wisdom says otherwise.

The key to winning in the NFL is an effective passing attack and an effective pass defense, regardless of how well or how poorly the run game performs. The Patriots of recent vintage, not to mention many other teams, provide plenty of examples.

But here are a few of the more notable examples:

The 2003 Patriots averaged 3.40 yards per attempt – far below the production of the 2008 Patriots. But the 2003 Patriots went 17-2 and won the Super Bowl, while the 2008 Patriots are 7-5 and will be lucky to reach the playoffs. Of course, the 2003 Patriots played lights-out pass defense and were a very effective passing team.

The 2007 Vikings provided a classic example of the futility of the running game without an effective passing attack. They fielded one of the best rushing offenses in NFL history and one of the best rushing defenses in NFL history. But they couldn’t pass the ball well so they went 8-8 and missed the playoffs.

The Steelers, meanwhile, are known for their consistently great running teams, going back more than 30 years. But the team’s determination and/or excellence running the ball only helped them win championships when they had a high-powered passing attack, whether behind Terry Bradshaw in the 1970s or Ben Roethlisberger this decade.

Solid: Kevin Faulk

The one constant in New England’s offensive backfield this year has been Faulk, the 10-year veteran and first-down-making machine, who’s having his best year in what’s already been a great (if underappreciated) career.

He’s the main reason the Patriots ground game has been historically effective, averaging 6.1 yards every time he runs the ball. It’s easily the best mark of his career and one of the best in team history (his previous best came in 2002 when he ran 52 times for 271 yards, or 5.2 YPA). Yes, he’s only had 73 attempts – but the production has been awesome.

And there’s more: Faulk is also on pace to set a personal best for receptions and receiving yards in a season, too. He’s already caught 43 passes for 363 yards through 12 games. In his best season (2000), he caught 51 passes for 465 yards.

Granted, Faulk has never been an every-down back. So his body has been spared the pounding that a LaDainian Tomlinson or the other great dual-threat backs in history have suffered.

Still, that doesn’t change the fact that, at 32, Faulk has been the most explosive force in New England’s offense, performing at a level few do at his age.

Rotten: Third-Down Defense

Richard Seymour was on WEEI this week lobbying for more playing time on third down. I don’t know if his lack of third-down playing time is a problem. But I do know this: the Patriots are abysmal on third down. You do the math.

The Patriots have allowed opposing offenses to convert 45 percent of their third-down attempts this year. Only the Bengals, Chiefs and Colts are worse – and two of those are among the worst teams in football.

In fact, along with its struggling pass defense, New England’s greatest liability on either side of the ball is an inability to get off the field on third down – as we learned Sunday when Pittsburgh converted 8-of-16 third-down attempts against the Patriots.

Seymour may or may not be the answer … but maybe it’s time we found out.

Solid: New England’s Ability to Recover From the Pittsburgh Loss

The quarterback threw two picks, was sacked multiple times and the ball carriers lost multiple fumbles as the Patriots lost by double-digits to the Steelers.

Only it wasn’t last Sunday’s game: it also describes New England’s 34-20 loss to the Steelers back in 2004.

If you thought this week’s drubbing by Pittsburgh was bad, go back and look at the stat sheets from that game back in 2004 that ended New England’s original 21-game win streak. The Patriots turned the ball over four times, they ran for a grand total of just 5 yards (on 6 attempts), and they lost the time-of-possession battle by an astounding 42:48 to 17:02.

Rod Rust’s Patriots rarely ever played so poorly, let alone Bill Belichick’s.

But it wasn’t the end of the world and it did not prove a precursor of things to come: the Patriots were virtually unstoppable the rest of the year and won the rematch at Pittsburgh, 41-27, in an AFC title game that bore no resemblance to the first meeting.

I’m not saying history will repeat itself. What I am saying is that you can draw too much from one loss – especially a loss in which the Patriots essentially turned over the ball on five straight possessions (if you include Matt Slater’s fumbled kick return).

If the Patriots hold on to the ball in a potential playoff rematch with Pittsburgh, there’s no reason to believe the game will be anything but competitive, right down to the wire.

Rotten: The “Matt Cassel Has Been Exposed” Crowd

Look, Cassel didn’t cover himself in glory against Pittsburgh, with his four turnovers on four consecutive possessions that, more than any other factor, cost the Patriots the game against the Steelers.

But young quarterbacks have bad games. If you take the Wayback Machine to 2001, you might remember that a certain future Hall of Famer named Tom Brady imploded in front of the country, too, in his first year as a starter.

He began his career going four-plus games without throwing a single pick. It was a remarkable stretch of discipline by a young passer. But then, in his fifth NFL start, in a game at Denver in late October 2001, his world crashed down around him with a dismal four-pick performance in a 31-20 loss.

The way I remember, he managed to recover quite well from that game.

Solid: A Fortuitous Remaining Schedule

The good news for the Patriots is that they have four very winnable games ahead of them to close out the season. Their next two games are against Seattle and Oakland, two of the worst teams in football. The Patriots should easily win both. And if they don’t, well, they don’t deserve to be in the playoffs. Then they host Arizona – an explosive offensive team but a team, like the Patriots, with big problems on defense. Then they close out the season against a Buffalo team that’s disintegrating before our very eyes.

It’s quite possible, even likely, that the Patriots end the season 11-5 and roll into the playoffs with a four-game win streak and the dismal loss to the Steelers a distant memory. The Patriots clearly have too many flaws to make a serious run at the Super Bowl – bad pass defense, bad third-down defense and unproven QB high on the list. But considering everything the team’s been through, it’d be a pretty remarkable result.

Now, for a root canal, that wasn’t very painful, was it?

Kerry J. Byrne is the publisher of ColdHardFootballFacts.com . His self-congratulatory column will appear here each Wednesday during football season. Send fawning praise, death threats or pictures of your 19-year-old sister to contact@coldhardfootballfacts.com.