Phoenix ? Discussions about greatness in sports often start with numbers but inevitably veer into something that is as graspable as vapor. Numbers measure; hearts decide.

The Patriots are 18-0 and need to beat the Giants in the Super Bowl to become the first team since the 1972 Dolphins to complete a season undefeated.

By all rights, the sports world should be reacting to the Pats’ accomplishments the way it might if someone were on the verge of surpassing Joe DiMaggio’s 56-game hitting streak or if a team were close to matching the Boston Celtics’ 11 NBA titles in 13 seasons.

The Patriots’ season should be launching the kind of flowery verse once reserved for explorers who brought home riches to the royal family, or, if that’s too monarchical for you, the kind of flowery verse once reserved for the patriots, lowercase, who fought for the American Colonies. Hey, sports writers under the spell of free buffet-line food have been known to get carried away.

But there’s something missing here, something about the Patriots that doesn’t quite live up to what the numbers insist is history in the making. They don’t capture the imagination. They tug at the imagination, but they don’t grab it, don’t shake it, don’t insist on being heard.

In a league beholden to the idea that every team should have an equal chance of winning a title, the Patriots have been marvels at judging talent and massaging the salary cap. For poetry purposes, what rhymes with “salary cap”?

The team from New England is about as romantic as a budget report.

Sure, there is the suave, marketable and very talented quarterback, Tom Brady. There is the one-dimensional, single-minded football savant, coach Bill Belichick. And there is the reined-in, ultra-athletic wide receiver, Randy Moss. In terms of star power, that’s it.

The Patriots are an ode to teamwork, and goodness knows we don’t have enough of that in professional sports these days. But when a team has the audacity and ability to go 18-0, the bar is raised very high. The discussion here centers on greatness, not on cohesion or choreography.

Newspapers and sports talk shows have devoted lots of time and space this season to debating whether the Patriots are the best team in NFL history.

Short answer: Um, no.

Long answer: Not even close.

As tired as some of us are of the mouthy ’72 Dolphins, that team was filled with great players, including Bob Griese, Nick Buoniconti, Paul Warfield, Larry Csonka, Larry Little and Jim Langer, all Hall of Famers.

The Steelers teams that won four Super Bowls in the 1970s had nine future Hall of Famers: Terry Bradshaw, Franco Harris, Mel Blount, Mean Joe Greene, Jack Ham, Jack Lambert, Mike Webster, Lynn Swann and John Stallworth.

Here’s another question, greatness connoisseurs: Can you be considered great if you have been caught cheating?

Hanging over Super Bowl XLII is the dark cloud of the Patriots’ spying scandal. The NFL fined Belichick $500,000 and made the team pay $250,000 and cough up a first-round pick in the 2008 draft for using a video camera to steal defensive signals from the New York Jets during a game early this season.

On its own, the scandal has taken some of the luster off New England’s accomplishment. But in the current climate of doubt and suspicion in sports, it has fueled further the discussion of what, if anything, is real in the games we watch for pleasure.