Since the NFL can’t make the Giants give back their Super Bowl rings, it’s probably safe to disclose a little secret that is known only to everyone who had a television set last season: The Giants really weren’t the best team in the league last year, or even the best team in their own conference. The Dallas Cowboys were, and if it hadn’t been for injuries and bad luck, the Philadelphia Eagles probably would have been.

Last year, the Cowboys whipped the Giants solidly, twice, by a total of 21 points in two regular season games and posted a 13-3 seasonal mark to the Giants’ 10-6. Dallas scored 455 points in 16 games and allowed 325; New York scored 373 and gave up 351. I don’t recall any year in which one team in a division so thoroughly dominated another over the course of the season only to lose to them in the playoffs. As for the Eagles, preseason favorites of many to take the NFC title, last season they managed to lose four games by a total of 13 points. Reversing two of them, including a 13-16 loss to the Giants, would have put Philadelphia in the playoffs instead of New York.

With their thrilling and ridiculously sloppy Monday night barn burner in Dallas, won by the Cowboys 41-37, the Cowboys and Eagles served notice that the NFC crown is up for grabs, whether the Giants want to acknowledge it or not. Due to an oddball scheduling quirk logical only to the NFL, the Cowboys and Eagles won’t get a crack at the Giants till the second half of the season — actually, not until Week 9, when Dallas comes to the Meadowlands on November 2. Then the Giants will play four games in eight weeks with their bitter division rivals, a round robin that will almost certainly determine the NFC’s Super Bowl representative.

Right now, any observer who isn’t a Giants fan would probably put their money on the Cowboys or the Eagles. For one thing, Dallas, despite the Giants’ amazing performance in the postseason, has a better defense, and the Eagles, who gave up fewer points last year than either the Cowboys or Giants and are now shored up by former Patriots all-Pro cornerback Asante Samuel, may have a better defense than both.

For another, until further evidence proves otherwise, the Cowboys and Eagles have better quarterbacks. Tony Romo, whose name and profile look as if they were provided by central casting, is probably the most talented quarterback in football. His career record of 8.43 yards per throw makes Eli Manning’s 6.35 seem anemic in comparison, and he has averaged a touchdown pass every 15.6 throws in his career to Manning’s one every 23.4 passes. But Romo has a major drawback: lack of experience. This is just his third season as a starting QB — which manifests itself in reckless throws and numerous unforced mental errors. (He’s like a talented but less experienced Brett Favre.) Also — and this is no small point — Romo is 28 years old and not likely to be getting better as he approaches the point in his career when the hits take a toll on his physical skills.

Eagles QB Donovan McNabb, on the other hand, has plenty of experience. The most talented quarterback of his generation when he came out of Syracuse in 1999, some observers thought he would be equally successful as a running back or strong safety or perhaps as a receiver. Though he’s had some success as a pro — he did, after all, take the Eagles to the 2005 Super Bowl against a superior New England Patriots team and lost by only three points, 24-21 — he’s had mostly rotten luck in his NFL career, starting with being drafted by the Philadelphia Eagles, the most unpredictable franchise in the league and the one with the nastiest home crowd. McNabb is 17th in the NFL’s all-time passer rating (two notches ahead of Favre), but you get the feeling that nothing he ever does will satisfy Eagles fans. If he won a Super Bowl, they’d just complain that he didn’t win another one.

Plagued by indifferent blocking, inconsistent receivers (except for Terrell Owens in 2006), and injuries, McNabb has nonetheless put up some impressive numbers. From 2004 through last season, despite missing 14 games, he’s thrown for 12,353 yards with an excellent 7.4 YPA and a terrific ratio of 84 TD passes to just 30 interceptions. Returning this year from an ACL operation, he still has extraordinary agility and foot speed, which he now uses mostly to give his downfield receivers a chance to break free.

After two games, McNabb appears to be headed for his best season. And, at age 32, not a minute too soon. So far he’s thrown for 642 yards with an eye-opening 9.2 YPA, four TDs, and no INTs. Next week the Eagles will play at home against a very good Pittsburgh Steelers squad, but after that, there’s a nondivision schedule that should give them less trouble than Sarah Palin being interviewed by Sean Hannity. Philadelphia’s three biggest games will be against the Giants on November 9 and December 7, and, finally, a season-ender and chance for revenge against Dallas in Philadelphia on December 28. Those three games will define the Eagles 2008 season, and, probably, Donovan McNabb’s career.

Mr. Barra is the author of “The Last Coach: A Life of Paul ‘Bear’ Bryant.”