CHIP KELLY'S first season as the Eagles' coach has been a revelation. His systems are innovative. His players are well-coached and improving during the season. His team is better than anyone expected.

And now comes the real test:

Can Kelly own December, as Andy Reid did?

Reid's teams used to dominate the stretch run of the NFL season. There were two truths about Reid's run with the Eagles - that they were impeccable coming off of a bye and that they were a machine after Thanksgiving. It happened every year.

From 2000 to 2009, the heart of Reid's success, the Eagles won 72 percent of their games in the last 5 weeks of the season - a number that would have been even higher had Reid not been uber-cautious about resting players after his playoff seeding was set. Pittsburgh also was at 72 percent. Only the Patriots, at 78 percent, had more wins.

The operating theory, bought into by almost all of Reid's players, was that their tough training camps somehow prepared them for the rigors of December. They all said it, and it was a nice narrative and, hell, I probably wrote it a half-dozen times over the years. They were all convinced that all of that hitting up at Lehigh got them ready for something that was happening almost 4 months later. I can still see cornerback Sheldon Brown standing there and insisting that it was so, and talking about how he considered it his duty to tell the story to the new players every year when they were complaining during the summer.

Reid's reputation was made down the stretch every year. It has been true for a long time now, that as long as you don't shoot yourself out of it in the first two-thirds of an NFL season, the final third is when the real is business is done. If you are hanging around .500 at Thanksgiving, there is still time - because, again and again, we have seen that a hot team at the end of the season is the most dangerous of species.

With that, whaddya got, Chip?

After a bye week of self-scouting and scheming, you have to wonder what Kelly has coming on Sunday for the Arizona Cardinals. Here is the best guess:

That they will try to play faster. If you look at the first half of games this season - before the score starts to dictate how you play - the Eagles have run the third-most plays in the NFL. But they can go faster. We have seen it in smallish doses, the super-revved offense, but not for long periods of time. Against a team with as much defensive talent as the Cardinals have, it could be an interesting way to go.

We could guess on other wrinkles, too - more tight ends, as we saw during the summer; more inventive formation things designed to get the ball to wide receiver DeSean Jackson even more - but all of it is just guessing. Andy Reid, we knew. Chip Kelly, we don't.

With all of this, we have been treated to a splendid holiday sideshow - the comment by Arizona coach Bruce Arians that the read-option offense is a good college offense, but that he is skeptical that NFL quarterbacks will be able to run it persistently because they will get killed by the superior defensive athletes in the pro game.

Arians is not wrong. Everything about the NFL is risk and reward, and you can see that by the way Kelly runs his offense. The Eagles run a lot of plays that look like the read option. In theory, the quarterback reads what the defensive end is doing and has the option to give the ball to the running back or keep it himself. The reality, though, is that as often as not, it doesn't matter what the defensive end does - the quarterback, be it Michael Vick or Nick Foles, just gives the ball to the running back.

The way it looks to a civilian is that, in the Eagles' offense, the quarterback needs to run the ball X-number of times per game, just to keep the unblocked defensive end somewhat honest. But "X" is not a big number. It is entirely doable. There is a risk, yes, but I'll go back to what Buddy Ryan used to say about Randall Cunningham: The hits you take in the pocket are worse than the hits you take running the ball.

Again, it is all about managing risk. And two or three or four runs per games into a wide alley vacated by that unblocked defensive end is manageable - especially if the quarterback is smart enough not to be greedy, and to find a soft spot to land before the hit can come at his legs.

Foles seems to understand that. He is coming off the greatest statistical month an NFL quarterback has ever had. He and Kelly and the rest of them have had a week to recharge and reconsider what is ahead.

December. It is the month when NFL teams start telling the truth about themselves.