shortly after a loss in the Super Bowl to the Kansas City Chiefs last February Kyle Shanahan fired defensive coordinator Steve wils and subsequently promoted Nick soron as defensive coordinator citing scheme fit and scheme philosophy as areas of dissonance and in need of change but what differences from wils to Soren and con 49ers fans expect to see this season one of the biggest areas will be in the pressure packages and coverages the team utilizes this season compared to last season under wils the coverage of the secondary was the focus allow more complicated disguises and changes to create Advent vantageous matchups while asking the front to win their one-on-one matchups as a couple of examples here from the Super Bowl against the Chiefs we see wils presents the chiefs with a man coverage look with a single safety and what we call a Middlefield closed look but the late motion of the Chiefs exposes the defense as Zone and post Snap they have dropped into a two deep four Under Fire Zone middle of the field open defense the Chiefs have a good call against this with a middle clearing route to pull Fred Warner deep and allow Travis Kel to work underneath that Nets them a first down on started along at a crucial point in the game from the endzone you can see the scheme provides one-on-one pass rushing challenges for the defensive line to win while trying to force momes to work post Snap to the change of the defense ideally giving the secondary an advantage and asking the talent up front to win their matchups later on another crucial third and down wils presents a pressure look with a Middlefield open defense with split safeties from here they drop into a three deep three underneath fire zone with Randy Gregory and Chase young dropping into hook zones late this time the Chiefs have Jerick McKinnon on a flare out and are again able to beat the pressure for a first down from the end zone the presentation shows the offense eight potential rushers against six potential blockers but will drop out three men into coverage they do get an unblocked rusher but the late drop of the two defensive ends doesn't account for the running back well and again leaves the defensive line with one-on run rushing challenges so so far in the preseason Nick senson has brought back pressure packages that were run under Robert Salah and Deo Ryan which provides greater advantage to the defensive line in their Rush opportunities but tasks the coverage with more predictable assignments here they give a pressure presentation with a single safety look post Snap they're playing a three over2 cone on the number two and number three receivers while Manning up the outside and having Robert be on a peel Rush where he will pick up the running back should he flare out into the flat [Music] from The End Zone the presentation forces a predictable line slide and with be on a peal Rush will ensure Malik Mustafa will be unblocked off the edge with the running back stepping up to pick up the inside pressure Robert Beal needs to recognize this and attack the offensive tackle to his inside shoulder to allow Malik Mustafa to have a direct line to the [Music] quarterback for another example example against the Saints soron is giving a bump man look with pressure post Snap you can see they are in a physical press man coverage while running a double stunt up front to generate a pass rush the presentation again will force a predictable line slide and opens up a huge Lane on a stunt the idea is to disrupt the timing between receiver and quarterback all four of these defensive calls allowed gains in different ways the last being a pass interference call but you can see a clear philosophical change from wils to Sorenson back to what the 49ers did under Robert Salah and Deo Ryan whereas Salah and Ryan focused on creating favorable matchups for the line in their pass scheme while keeping things more simplified on the back end wils focused on keeping things more complex and favorable for the coverage units while keeping the front more simplified will the 49ers defense see a return to form that fans were used to seeing under solah and Ryan's that's the question that will need to be answered this season but the early evidence shows that fans can expect a scheme change much more aligned to the former than the latter