Between mid-August and the season opener on Sept. 10 last year, the Eagles made 60 separate player transactions. They signed, waived, traded, released, designated and otherwise altered the football careers of nearly enough players to outfit a full roster.

That wasn't anything particularly unusual, either for the Eagles or any other NFL team that annually makes its final decisions in an immense flurry before the start of real games. The last battles for spots on the 53-man roster are decided. The cuts made by other teams are picked over for compatible pieces. The practice squad is formed. The ranks of the injured and injured-reserve lists are made official.

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What was different in 2017 was that the final rush of moves, mostly in small ways, but not always, added up to winning a championship. If the devil is in the details, so is the trophy, and that is something the coaching staff and front office will keep in mind in the three weeks that remain until the season opens.

On the one-year anniversary of the trade that brought in cornerback Ronald Darby and sent off receiver Jordan Matthews and a draft pick, Doug Pederson was asked if he ever considered the "butterfly effect" of certain roster moves. It is the idea that one thing leads to another eventually, often in unexpected and unpredictable ways, like the theoretical beat of a butterfly's wings that begets a hurricane a continent away.

"The butterfly effect? What?" said Pederson, who was probably expecting something else.

In that particular case, however, the effect of trading for Darby became exactly what the Eagles were hoping for, not something unexpected. He fought through injury, eventually became a starter and the depth that was built in his absence made defensive backfield one of the team's strengths.

"You bring somebody in that can solidify that corner and now it frees up a couple of other guys to give you depth at the nickel position and also backup corner position," Pederson said. "It's all part of the bigger picture."

The trade was only one of those 60 transactions, and they were all part of the bigger picture. Subtracting Matthews did give receiver Nelson Agholor an opportunity to blossom that might not have come otherwise, or been predicted, so perhaps there was a butterfly in the air for him along with 62 receptions and eight touchdown catches.

If you want to name the move from last year with the most profound unintended consequence, that's easy. On Aug. 28, the Eagles traded long snapper Jon Dorenbos to the Saints in exchange for a seventh-round draft pick. When he arrived in New Orleans and was examined by team doctor John Amoss, it was discovered that Dorenbos had an aortic aneurysm. He underwent immediate open-heart surgery to repair the aneurysm, which, if it had gone undetected, could have killed him at any moment. The trade, quite literally, saved his life.

Well, it's going to be tough to top that one this year, and the decisions will probably lead to far more mundane consequences. It matters very much, however, to Kamar Aiken, Markus Wheaton and Shelton Gibson which of them the coaching staff chooses to keep at wide receiver.

The battle for cornerback playing time between Avonte Maddox and De'Vante Bausby; the shoving match between tight ends Richard Rodgers and Billy Brown for a possible roster spot; the endless speculation over the identity of the fourth running back from the grab bag of Matt Jones, Donnel Pumphrey, Josh Adams and Wendell Smallwood – all of that will continue for two more weeks. Those calls and a couple dozen others will have to be made, and then the transaction wire will overheat and the final roster will be set.

A year ago, there was speculation at this point of training camp that the Eagles would look to move center Jason Kelce and that there might not be a spot at defensive tackle for Beau Allen. Some of the same backups who are still pushing for playing time were predicted to step up and make their claims. It didn't happen that way. Some others, like cornerbacks C.J. Smith and Aaron Grymes, safety Terrence Brooks, and linemen Matt Tobin, Dallas Thomas and Dillon Gordon, were given slots on the 53-man projected rosters that are always more interesting than accurate at this time of year.

Some players stayed, some players left and there were surprises in both groups. And still, the comings and goings, the five dozen transactions as the season approached, ended in Minneapolis against the New England Patriots.

More than a few of this season's decisions will probably be made Thursday night when the two teams meet again. Players will rise and fall. They will leap onto the roster or drop from it. It happens every year as the coaches and front office sort out the coming moves. Rarely do they get them all right, but that's the idea. When it works, though, as it did last season for the Eagles, the final product is a roster as complex and pleasing as the pattern on a butterfly's wings.