How will the Eagles defense change — or stay the same — under new Sean Desai?

INDIANAPOLIS — After considering nine candidates over two weeks, the Eagles decided on Sean Desai.

The rationale is clear enough. The 39-year-old was one of the strongest candidates from the outset. He spent 2006-10 at Temple and quickly impressed those around him, according to those coached alongside him. Most importantly, though, may be Desai’s experience and aptitude running Vic Fangio’s scheme.

Fangio is the architect of the split-safety defensive structure that has become paramount across the league and was coveted by the Eagles. The team’s pool of candidates had a wide range of systems and philosophies, but Desai offered the Eagles a chance to stay true to the way Nick Sirianni, Howie Roseman, and Jeffrey Lurie believe defense is best played.

Sirianni will certainly capitalize on the uncertainty that comes from a new defensive coordinator succeeding Jonathan Gannon, but there are plenty of clues as to what scheme Desai will run. The similarities between the two coaches are apparent, and Sirianni said the continuity in the two schemes was a selling point for Desai.

“What I did like is some of the similarities to the things that we do,” Sirianni said Tuesday. “That we’ve already been doing here on a very successful defense with different coverages, different run blitzes, things like that.”

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Referencing back to Desai’s 2021 season as the Chicago Bears defensive coordinator, it’s easy to see those commonalities and differences to the Eagles’ scheme the last two seasons. Here are the ways things will change — and stay the same — for the Eagles defense next season:

One of the biggest differences between Gannon’s scheme and Desai’s will be pre-snap presentation.

Both use a mixture of odd and even fronts depending on the situation, but the creativity with which they deploy them is where the contrast lies. Desai used a handful of unconventional splits, especially in known passing situations, to create confusion. Against the Rams in 2021, the Bears lined up in a front featuring two one-technique defensive tackles and two wide-nine edge rushers, creating gaping holes along the interior in favor of testing the offensive line’s capability to protect against a foreign look.

The Bears would also run overload fronts with three defensive linemen to one side and just one rusher on the opposite edge, leaving the weak-side interior completely uncovered.

Desai would also sometimes line up his two best rushers (Khalil Mack and Robert Quinn) on the same side in an effort to exploit matchup advantages. With all the creative fronts, Desai would call plenty of twist stunts or similar games, having defensive linemen shoot specific gaps instead of rushing straight ahead to stress the offensive line’s coordination.

Gannon’s approach was mostly to line up four or five rushers in their typical spots and let them rush with the occasional twist stunt to free someone up. To be fair, Gannon’s deployment of the Eagles’ defensive front led to one of the most productive seasons from any pass rush in league history. Running games up front is sometimes an indication of a coach scheming things up for a group with less talent than the Eagles have. Still, even with talented edge rushers in Chicago, Desai showed he could maximize their talent with the complications.

While the front mechanics will change considerably, the number of rushers will likely resemble the Eagles under Gannon.

Desai’s blitz rate during his year running the Bears was 22.6%, which is nearly identical to the Eagles’ rate last season (22.1%). It’s unclear how much Desai influenced this, but it’s worth noting the Seattle Seahawks blitzed 15.2% of the time last year, which ranked 31st in the league. Desai’s title with Seattle was assistant head coach/defensive assistant.

It’s safe to say the Eagles aren’t returning to the days of Buddy Ryan or Jim Johnson with the Desai hire, but a blitz rate around 22% is more or less in line with Fangio-influenced schemes. The Bears were still effective without blitzing. They ranked 17th in pass-rush win rate, which measures how often a team gets pressure within 2.5 seconds, but finished third in sacks.

The diversity in alignments up front will likely extend to the back end as well. Both Gannon and Desai prioritized disguising coverages pre-snap, but they go about it much differently.

Gannon’s disguise was in uniformity; cornerbacks and safeties would stay in the same alignment for most calls, typically putting the outside cornerbacks in off coverage and two safeties over the top. The confusion for quarterbacks is supposed to come post-snap, with the possibility of the secondary rotating into several different coverages.

Desai’s history indicates he is more willing to change up the picture pre-snap and post-snap. His cornerbacks have more diversity in their alignments and line up close to the line of scrimmage in press coverage more often than the Eagles did last year. The Eagles were typically content giving receivers free releases off the line of scrimmage in favor of limiting big plays under Gannon. Desai’s version of the Bears defense called for much more physicality at the line of scrimmage to jam receivers before dropping into zones.

Some of Desai’s press calls may have been to fit the Bears’ personnel, but it will be an option for the Eagles, especially if they select a physical cornerback in the first round of next month’s draft.

» READ MORE: Eagles need to find a cornerstone in this year’s NFL draft. It would help if it’s at cornerback.

The alignments will change, but the coverage calls should look mostly the same with Desai.

Desai called zone coverage 64% of the time with the 2021 Bears, using man-to-man 28% of the time. By comparison, the Eagles went with zone 71% of the time and were in man 23% of the time.

Both use two deep safeties most of the time, but Gannon gravitated more toward single-high looks in his second year and Desai uses them a good amount as well. Desai, a former secondary coach, uses a bit more creativity, but it’s still based in the Fangio system of zone coverage with deep safeties to limit explosive plays.