Most of the National Football League -- or at least the part that thinks -- is looking toward Baltimore and Philadelphia today and shaking its head in puzzlement. The reason is the rise and fall of two coaches; the dominant question: How could the one with exquisite talent drop so dramatically while the one with little more than culls succeeds beyond belief.

It will take a more persuasive argument than any Colt owner Robert Irsay will muster to convince many NFL watchers that the coach he fired yesterday, Ted Marchibroda, cannot coach. Yet the Colt's decline during Marchibroda's fourth and fifth years was nearly as drastic as their improvement during his first.

And that had been as great a tournaround as any in NFL history, from the worst record in the AFC (2-12) to 10-4 and AFC champions. That was in 1975. A year later Marchibroda won a management fight with General Manager Joe Thomas and the Colts went 11-3.

They lost both first-round playoff games to the decade's best team, the Pittsburgh Steelers, but their future seemed bountiful, their potential limitless, with the sport's best young quarterback, a tireless runner, fine blocking and a young, tough defensive line.

While the Colts were seen as soaring toward the NFL's ionosphere -- if not quite as high as Pittsburgh -- insiders were taking pity on the cherubic-looking Dick Vermeil, wondering what such a bright young man was doing as coach of the Philadelphia Eagles.

Vermeil had been lured away from making UCLA the Southern Cal of Los Angeles that year -- and asked to rebuild a team with almost no tools. His was a Pardee-like dilemma, only worse. He had no draft choice higher than No. 4 the first year and went 4-10, in contrast to Marchibroda's 11-3.

Worse, Vermeil had no draft choice higher than No. 5 the next year and nothing higher than No. 3 the next. The Colts had a full complement each season. So what is Vermeil, doing in the playoffs this year, after an 11-5 season, while Marchibroda is fired after a 5-11 record?

All anyone can offer immediately are clues rather than answers, the suggestion that Marchibroda's decisions off the field were more harmful than the ones immediately before and during games and that the fate of both men was steered by the sort of luck that defies explanation.

For instance, Marchibroda endured most of the last two seasons without quarterback Bert Jones. Probably, he still would be the Colts' coach today, possibly still regarded as a genius, if Jones had not been injured so often.

Consider the Steelers without Terry Bradshaw, the Cowboys without Roger Staubach, the Redskins this season without Joe Theismann. Jones meant at least as much to the Colts -- very likely more.

Few, if any, NFL coaches become outstanding without an outstanding quarterback -- and Marchibroda won 75 percent of his games and three AFC East titles with Jones completely healthy.

But there were signs of erosion while the Colts were basking in the NFL spotlight, hints that they would begin to slide even if Jones had remained at full strength.

The NFL lifeline is the draft -- and the one that feeds the Colts has been leaking badly the last three years, or ever since Marchibroda won that battle with Thomas. In truth, the last four drafts have been awful.

When their two strong areas were wide receiver and the defensive line, the Colts' top draftees the first year of Marchibroda's expanded authority were a wide receiver and a defensive lineman.

Also, there were an inordinate number of injuries in addition to Jones. But in the NFL the major ownership question is not how games are won but how many. And while the Colts and Marchibroda were unfortunate and injudicious with the expensive material at hand, Vermeil built a sturdy machine with spare parts and chewing gum.

Or at least with players hardly anyone else wanted. On the roster for the 27-17 playoff victory over the Bears Sunday, the Eagles had just two first-round draft choices and more than a dozen free agents.

Vermeil's first full draft was this season. Of their 10 choices six made the team and four became starters. They also lost an important player, linebacker Bill Bergey, considered by some to be their defensive Bert Jones. Yet they improved a 9-7 record to 11-5 in the leagues's third-toughest division.

Their unexpected good fortune came during the draft, though they considered it a terrible blow at the time. They went into the draft confident Russell Erxleben of Texas would fill their considerable need for a punter and placekicker.

But New Orleans chose him on the first round. So the Eagles took a linebacker, Jerry Robinson, with their first-round pick and chose placekicker Tony Franklin on the third round and punter Max Runager on the eighth.

All three have been spectacular at times, the equivalent in retrospect of swapping one high first-round choice for three low first-round choices. And the lost savior, Erxleben, missed most of the season with an injury.

Marchibroda and Vermeil are not quite at opposite ends of the coaching spectrum. But Marchibroda often commuted daily from northern Virginia to Baltimore while Vermeil often sleeps in the office several nights each week.

Vermeil cherishes his workaholic image, the fact that after the Eagles beat the Cowboys in Dallas this season he kissed his wife, known as Saint Carol, goodbye at the airport at 4 a.m, and sped to the office.

Other NFL coaches work nearly as hard, but talk about it less. And the turnover rate among Eagle assistant coaches is among the highest in football.

Marchibroda is a fine man who proved himself a fine coach when he had fine players. He was hired by an owner given to judgments and a gifted general manager who would tolerate no intrusion on his authority.

Together, Marchibroda and Thomas might well have been unbeatable. Apart, both are out of the NFL.Marchibroda had dreamed of becoming a head coach for years. Now he realizes there is so much more to coaching than coaching.