The answer is that there is no true answer.
“I think it just really depends on who we’re playing,” said Notre Dame head coach Brian Kelly on Monday after the team’s first spring practice. “It’s so easy now to get in and out of the three-down (lineman) and the four-down defense, that’s the way we’re going to construct it.
“It’s really going to be week-to-week.”
The Fighting Irish were suited for the 3-4 with big bodies in the middle who could command double teams, such as Louis Nix. With no real space-eater like that on the roster this spring, as well as the onus that is put on recruiting large tailor-made nose tackles, Kelly has made a move towards bringing in and developing players who can be moved inside and out on the defensive line or around the front seven.
Sophomore Jaylon Smith out of Bishop Luers may see his role change a little bit in his second season. Kelly appears to want his outside linebackers to blitz more around the edge, something Smith did not do much of a year ago.
Former Bishop Dwenger standout Tony Springmann is projected to be one of the top interior linemen for the Fighting Irish next season, but is still recovering from a significant knee injury that saw him miss all of 2013.
Springmann is being held out this spring but it is hoped that he will be 100 percent by the time fall practice begins.
“It’s really going to be more game-plan structured than it has been in the past,” Kelly said. “We’re going to be situationally three-down (and) four-down.
“We just need to continue to recruit some more of those guys that can get after the quarterback.”
Kelly’s hope is to develop several linebacker/defensive end hybrids that can rush off the edge with or without a hand on the ground. The versatility those players bring would allow Notre Dame to tinker with its defensive sets and not allow them to be pigeon-holed into either a 3-4 or 4-3.
“It’s going to be similar to what New England is doing,” Kelly said. “One week they might be all four-down the entire time and the next week they’re three-down.”