Doug Pederson was called “Skinny Andy” by some veteran players when he first took over as Philadelphia Eagles coach because of how closely his operation resembled that of his mentor, Andy Reid.

“I’m a big believer that you don’t change just to change," said Pederson, who played under Reid and was on his coaching staff both in Philly and Kansas City, including two years as the Chiefs offensive coordinator before landing his current gig. "It’s got to benefit the team, and it’s got to help you win games.”

Pederson has put his own spin on things as he’s grown into the job, but striking similarities in principles and approach remain. That is reflected in on-field performance through five weeks, as the 5-0 Chiefs and 4-1 Eagles have mirrored one another in many respects en route to power positions in their respective conferences.

Total offense:

Kansas City No. 2 (2,071 yards)

Philadelphia No. 3 (1,989 yards)

Passing yards/game:

Philadelphia No. 9 (259)

Kansas City No. 10 (258)

Chiefs head coach Andy Reid and Eagles head coach Doug Pederson talk before their Week 2 game, won by the Chiefs. AP Photo/Charlie Riedel

Reid is in his 19th season as head coach -- the first 14 of which were with the Eagles. He has become the 11th winningest coach in history (178) over that time. Former NFL defensive back and current ESPN analyst Matt Bowen believes Reid remains one of the best play-callers in the game because "he has adapted to modern football," incorporating spread concepts into his West Coast-based offense. That's partly because he wanted to maximize quarterback Alex Smith 's skillset by incorporating quarterback option schemes and run-pass options (RPOs) into the system. Pederson has done the same for Carson Wentz.

"If you turn on a Kansas City tape or a Philly tape right now, I bet you'd see it littered with RPO schemes," Bowen said.

Wentz and Smith have been among the league's best to this point, both ranking near the top in yards, touchdowns and quarterback rating.

Still West Coast at heart, much of the passing game emphasizes high-percentage throws over the middle. That's one of the reasons why tight ends are so highly valued in this system. Fortunately for Pederson and Reid, they have good ones in Zach Ertz and Travis Kelce, who rank first and second among tight ends, respectively, in catches and yards through five weeks.

"You talk about Ertz, you talk about Kelce, those are middle-field throws," said Bowen. "Rhythm passing, three- and five-step drops. In the three-step passing game, they're almost exact patterns of each other: they'll run slant/flat, they'll run stick/out with the tight end... a lot of it clearing out space. On top of the West Coast concepts, it's clearing out space."

Bowen notes that while West Coast offenses aren't typically associated with a lot of deep throws, Reid and Pederson have been taking plenty of shots. That has a lot to do with personnel. They both have speed receivers (Tyreek Hill in Kansas City, Torrey Smith and Nelson Agholor in Philly) who can shake loose downfield while opening up isolation matchups underneath.

Reid has been dressing his offense up more with different looks and motions to compensate for the lack of a traditional No.1 receiver, Bowen says, but the concepts are similar at their core.

Both ground games are a mix of zone and power and have been very effective. Kansas City boasts the league's top rusher in rookie Kareem Hunt, while LeGarrette Blount has helped fuel a resurgent ground game that found its footing, interestingly enough, after a lack of balance in a Week 2 loss to Reid's Chiefs. Both teams have been able to control the clock as a result, ranking No. 1 and No. 2 in time of possession.

Rushing yards/game:

Kansas City No. 2 (156)

Eagles No. 5 (139)

Time of possession:

Eagles No. 1 (35:32)

Chiefs No. 3 (33:03)

That has helped defensive units that have suffered big injuries, particularly in the secondary. The loss of safety Eric Berry for the Chiefs and cornerback Ronald Darby for the Eagles has left the back end more vulnerable, but the pressure has been eased by working opposite efficient offenses and alongside solid front sevens. The Eagles defense ranks 24th overall and the Chiefs' 29th, but they rank eighth and 10th in takeaways, which has helped keep the points-against numbers down.

"They both have pass-rushers. But both secondaries in my opinion are trying to find an identity," said Bowen. "If you were to ask me where I would attack both teams, that's where I'd go right now -- I'd go after the secondaries. And specifically, outside the numbers."

Whether that ends up hurting them as the season rolls on remains to be seen. But for right now, their respective strengths have student and mentor side-by-side at the top of the standings.