We can only wonder if the Andy Reid who coaches the Eagles now would have won a Super Bowl if he'd been around from 2000 through 2004.
That Andy Reid believed in a platoon of unspectacular but well-schooled wide receivers running his faithful version of the West Coast offense.
This Andy Reid is so taken by DeSean Jackson's electrifying skills that he chuckles when the second-year wideout risks his already injured (and drug-numbed) groin muscle with a somersault in the end zone.
That Andy Reid wouldn't let a running back as talented as Brian Westbrook play regularly until he had mastered the nuances of reading, reacting and blocking a blitz by a linebacker or safety.
This Andy Reid all but turned Sunday's game against the Chiefs over to rookie LeSean McCoy.
That Andy Reid would throw the ball a zillion times a game if he could, even in running situations like third or fourth and 1.
This Andy Reid - well, OK, so the big guy hasn't been replaced by an alien replicant. He has evolved, not changed completely.
But as the Eagles go into their bye week with a 2-1 record, with some real injury concerns and with the maw of their schedule awaiting them, by far the most intriguing subplot of 2009 is the radical change in the famously stubborn head coach.
During his news conference yesterday, Reid was asked about Jackson's ill-advised flip and about center Jamaal Jackson's savvy veteran observation that the kid could have put himself out for the season by landing in a split. The 2001 Reid would have seconded Jamaal's emotion. This Reid sided with DeSean.
"I always tell the guys to act like you've been there," Reid said of touchdown celebrations. "He's an exciting little guy. He adds a little spice to things. He puts his little flair on it. When I tell him to act like he's been there, he can tell me he's been there once or twice."
There's a chicken-and-egg element to Reid's relationship with DeSean Jackson. Did he change his thinking on playing young offensive skill players last year because Jackson was so talented? Or did Jackson have a brilliant rookie season because Reid changed his outlook and went with skill over mastery of the offense?
Either way, Jackson's impact has encouraged Reid's evolution. He used his first two picks in the 2009 draft on offensive skill players, and he has entrusted both of them, wide receiver Jeremy Maclin and McCoy, with significant roles early in their rookie season.
As Reid noted, the Eagles had 11 offensive players on the field at times Sunday with an average age of 24. That is stunning. It is even more stunning - given the coach's past tendencies - that the average age of the six skill players in the starting lineup was just 23.
But this isn't happening in a vacuum. Reid hasn't just started letting rookies run wild in his complex derivation of the West Coast offense. The offense has changed an awful lot, as well. More and more, Reid is running a version of the spread offense that bears little resemblance to anything Bill Walsh or Mike Holmgren was doing.
As former NFL head coach, Eagles coordinator and West Coast acolyte Jon Gruden told The Inquirer's Bob Brookover the other day, players coming out of college are familiar with the spread offense. The transition is much easier for Maclin and McCoy than it was, earlier in Reid's tenure, for Westbrook or Freddie Mitchell or Reggie Brown.
Of course, there is much to be said for any system, offensive or defensive, that gets the most out of players' skills and athleticism.
And that's why we have to wonder what might have been if this Reid had been coaching the Eagles early in Donovan McNabb's career. This spread offense, including its Wildcat or option components, would have been a natural fit for McNabb when he came out of Syracuse. And there's no doubt No. 5 would have benefited greatly from this zany new idea of flooding the field with fast, talented receivers and backs.
But we can't rewrite the past. Reid was hired here because of his offensive philosophy, and McNabb flourished after a year's apprenticeship in that system. If the Eagles hadn't been successful, Reid wouldn't have been around long enough to evolve and grow.
We can't write the future, either, of course. Reid's snazzy new playbook hasn't been exposed to the sharp minds and physical play of the league's better defenses. The spread and the Wildcat might well wind up in the waste bin after the Giants and Cowboys and Chargers and the cold weather get their cracks at it.
We don't know how this season will play out. What we know is that it won't be like anything we've seen in the Reid era, and that's something.