Eagles analysis: Jordan Davis and the run defense, Nick Sirianni’s 4th-down decision-making, Arryn Siposs

Other than calling the Super Bowl “a learning experience,” Jonathan Gannon didn’t go into detail about the Eagles defense’s second-half collapse during his introductory news conference as the Cardinals’ new head coach.

If he’s on the podium at the NFL combine in less than two weeks, Gannon is likely to see more Philadelphia-area reporters than Arizona-based ones, and many of the questions will be about the decisions or the ones the ex-Eagles defensive coordinator didn’t make in the final 30 minutes of the 38-35 loss to the Chiefs.

Coach Nick Sirianni, in the meantime, attributed the swing of halves to “situational football on third down and also the run game” during a season-capping interview Thursday with general manager Howie Roseman.

The Eagles surrendered two passing touchdowns on second-half third downs — vs. similar plays — but the Chiefs were able to get into manageable distances because of their success on the ground against a defense that had been susceptible most of the season to offenses committed to the run.

In the first half, the Chiefs averaged 8.6 yards to go on their three third downs and didn’t convert on one. In the second, they averaged 3.4 yards and converted their first four third downs. On the fifth — the longest at 8 yards — cornerback James Bradberry was penalized for holding.

» READ MORE: Jonathan Gannon and James Bradberry were a study in character and contrast after the Eagles’ Super Bowl loss

That pass-happy Andy Reid would take advantage of the Eagles’ run-defense weakness may seem ironic, but in the previous meeting between the Kansas City coach and Gannon last season, the Chiefs rushed almost as often as they threw and gained 200 yards.

On Sunday, they ran for 158 yards on 26 carries. While quarterback Patrick Mahomes contributed 44 of those yards on six scrambles, Chiefs runners gained 114 yards on 20 tries (5.7 average) with 86 of those yards coming after the break.

Gannon’s scheme is predicated on limiting explosive plays and with enticing offenses to hand off. On paper, taking the ball out of the hands of arguably the best quarterback in the NFL should be a win. But the Eagles got gashed on the ground, and it often didn’t matter whether Gannon employed a five- or four-man front.

The Chiefs entered the game using motion the fourth-highest percentage in the NFL (64.8) and motion at the snap the 13th highest (18.2), per ESPN. But the Eagles were often fooled, especially by ghost jet motion.

The eye candy motion often tricked second-level defenders, and sometimes had two players accounting for one player — in the below circumstance on a pass play.

“That’s part of their scheme. They try to get you out of position. They play trick football,” Eagles linebacker Kyzir White said. “They’re a hell of a team, but they definitely want to mess with your eyes.”

The Eagles’ defensive front was just as culpable and either struggled to get off blocks against a good Chiefs offensive line or were uncharacteristically undisciplined in their gap integrity. The interior, particularly nose tackle Jordan Davis, didn’t get much push or often failed to clog the “A” gaps.

Davis was relatively effective on run downs in the first half of the season. But the Eagles’ top draft pick suffered an ankle sprain and Linval Joseph was added midseason. Davis eventually returned, but he dropped behind the veteran as the Eagles started moving him to other spots along the line.

He eventually moved primarily back to the nose, but he never seemed able to recapture his pre-injury form.

With Gannon gone, Sirianni said he was open to selecting a replacement who uses a different scheme. Will he go as far as to choose one with a predominantly aggressive four-man front, one that could negate Davis’ size on run downs?

» READ MORE: Nick Sirianni plans to delegate duties to the Eagles’ replacements for Jonathan Gannon and Shane Steichen

The Eagles traded up in the first round for the 6-foot-6, 340-pound Davis because they believed he could develop as a pass rusher. He didn’t get as many snaps playing behind Fletcher Cox, Javon Hargrave, Ndamukong Suh, and Joseph, but with changes to come, the Eagles will need him to step up in his second season.

“He’s only going to continue to get better with the reps that he has,” Sirianni said. “He has unusual traits. His unusual size, unusual athletic ability, unusual play strength.”

» READ MORE: Where does the Eagles rookie Jordan Davis' future stand?

While there were plenty of individuals who didn’t perform up to their standards in the Super Bowl, it was mostly a collective failure on the defensive side of the ball as the Eagles failed to get one stop in the second half.

Players either weren’t prepared properly, Gannon’s calls didn’t optimize the situation, or he failed to adjust. The most prominent example of perhaps all three came on the Chiefs’ final touchdown.

On its previous drive, Kansas City took a 28-27 lead when Kadarius Toney ran an orbit motion vs. the Eagles’ man coverage that had cornerback Darius Slay switching off when he should have stayed on his man.

“There was an execution error,” Sirianni said.

The coach was quick to point blame at everyone for the mistake, but Gannon was chiefly responsible when the Chiefs went back to a similar play on their next possession. Kansas City was actually in the wrong formation and Reid tried to call a timeout.

But Mahomes still ran the play with a few seconds left on the play clock and receiver Skyy Moore was wide open and waltzed into the end zone. It’s unclear what cornerback Avonte Maddox was doing, but he was completely out of position.

Mahomes, via NFL Films audio, said on the sideline that Gannon’s “zero [blitz] was as clear as day.” Chiefs quarterbacks coach Matt Nagy observed, “That jet motion is killing them.”

Sirianni defended the call, noting the Eagles were in a different coverage — a matchup zone — and one that had served them well throughout the season.

“The second one, they got us,” he said, adding: “A lot of times that we’ve adjusted with that motion and the way we’ve done that has helped us a lot in the red zone.”

But Gannon’s unit got burned in the worst possible moment.

As poorly as Gannon’s defense performed in the second half, Siriann’s other units didn’t help matters. The Eagles offense went 60 yards on 17 plays on their opening drive of the third quarter, but settling for a field goal while the Chiefs were scoring touchdowns would come back to haunt them.

Sirianni couldn’t have known at the time how the game would ensue, and taking the three points instead of going for it on fourth-and-6 at the Chiefs’ 15-yard line late in the third quarter wasn’t as egregious as his punt a series later, according to various statistical models.

Trailing, 28-27, with 10:33 left, the Eagles faced fourth-and-3 at their own 32-yard line. Sirianni’s aggressiveness all season had been one of his hallmarks. He was successful on three prior fourth downs in the Super Bowl, but fourth-quarter fourth-down analysis becomes more complex because of time and score differential.

“I think you would get 32 out of 32 NFL coaches saying they punt that ball every time, Sirianni said. “Thirty-two out of 32.”

If true, then Sirianni’s conservative call there is more of a systemic one than an individual one. Models used by ESPN and Ben Baldwin of The Athletic had high win probabilities had the Eagles rolled the dice rather than punted. Sirianni wasn’t asked what his analytics team suggested in that scenario.

In Super Bowl LII, Doug Pederson went for it on fourth-and-1 at the Eagles 45, down 33-32, with 5:39 left. While the win probability numbers in that situation were much higher than they were for the Eagles five years later, Pederson was factoring the Patriots’ offensive success into his gamble.

Sirianni should have placed greater emphasis on the fact that his defense couldn’t stop Mahomes by that point.

“Hey, if I had known they were going to return it to the 4, in hindsight, I think obviously I would have gone for it there,” he said. “But no regrets there on that. That is not in my thought process right there.”

What maybe should have been in Sirianni’s thought process — or that of Roseman — was that sticking with punter Arryn Siposs would eventually sting the Eagles in a major way.

The decision to activate Siposs ahead of Brett Kern after his six-game ankle injury wasn’t the wrong one. Kern had failed to impress in his audition. But Siposs was statistically one of the worst punters in the NFL the last two seasons, and situationally in big spots he failed to deliver, notably in last season’s playoff loss to the Buccaneers.

When it came time for him to flip the field for the Eagles, he shanked a punt that was low and traveled only 38 yards.

“Arryn didn’t get the punt that he wanted there,” Sirianni said. “So, there was a low hang time. Toney did a good job of scooping that up and not letting it hit [the ground].”

Siposs’ errant boot set in motion a missed tackle and scrambling by the Eagles’ cover unit in which the punter ultimately had to tackle Toney from behind after a 65-yard return — the longest in Super Bowl history.

» READ MORE: Which Eagles should stay or go?

No roster is perfect. Roseman built maybe the most complete team in the NFL. It could be argued that if you’re going to go light at one unit, it’s special teams, especially with offensive aggressiveness and the restrictions placed on the return game.

The Eagles had any number of variables that affected them in the Super Bowl. Of course, there were certain areas that stood out negatively more than others. But, ultimately, they lost to a great team with a great coach and quarterback, and by the slimmest of margins.