Notre Dame football defensive coordinator, Bob Diaco, has had his ups and downs in South Bend, but by no means has his coaching been atrocious.
In 2010, the team gave up 24.89 points per game in the first nine contests. The defense seemed to hit its stride in the last four games of the 2010 season, allowing just 39 points (an average of 9.75 points a game) in four consecutive victories.
Many thought that momentum would continue in 2011, but stellar play only came in spurts.
The Irish gave up a respectable 20.7 points per game over the course of the year (good for 24th in the nation), but when the game was on the line, the defense faltered too often (late-game collapses against Michigan and Florida State have are still giving fans nightmares).
However frustrating the team's defense was at times in 2011, it is much improved from the Charlie Weis era.
The biggest complaint about Diaco is that he is often too conservative in his play-calling, and while I agree that the defensive coordinator could attack opposing offenses more, the Irish defense doesn't need a complete overhaul. They just need a slight adjustment.
Aggressive defenses don't always work. Playing aggressively too often leads to big plays for offenses, and if a team doesn't have the right personnel, the results can be disastrous.
John Tenuta, who was named co-defensive coordinator with Corwin Brown under Charlie Weis in 2008 (after Brown's defensive schemes weren't working), called blitzes on nearly every down. While those same calls worked wonders for the Georgia Tech defense Tenuta oversaw just one year prior, the Irish defenders simply couldn't get to the quarterback no matter where they were blitzing from.
As time went on, and as Notre Dame consistently gave up big yardage to its opponents, Tenuta's approach became more conservative. He did help the defense improve during his tenure, but statistical improvements didn't cover up the fact that Notre Dame's defense was a glaring weakness.
Diaco hasn't struggled nearly as much as Weis' staff did on defense, and the defensive personnel has improved enough to the point where a conservative approach can work without giving up a staggering amount of yards per game.
Notre Dame coaches are probably banking on Stephon Tuitt and Aaron Lynch being so disruptive that sending a linebacker after the quarterback on occasion will be sufficient, but the Irish would benefit from a slightly more aggressive, calculated defensive attack.
Notre Dame has the players needed to get to the quarterback: a number of talented defensive ends, powerful, fast linebackers and defensive backs who can fly into the opponent's backfield.
Speedsters like Bennett Jackson, Josh Atkinson or Jalen Brown (and possibly Davonte Neal) could contribute to a blitz package from a cornerback spot (most likely nickel). Jamoris Slaughter, Austin Collinsworth, Dan McCarthy or Elijah Shumate could attack the quarterback from a safety spot.
Ben Councell, Ishaq Williams and the talented pass-rusher, Manti Te'o, should also get their numbers called on more than just a rare occasion.
Against some teams, Diaco's conservative approach worked well, but teams with an emphasis on the passing game should see a healthy dose of blitzes in 2012.
I don't think many fans want to go back to the days under Tenuta where opposing teams called quick-hitting plays to counteract what they knew was coming—a blitz—but the talent on the roster also needs to be utilized.
However, of those four schools (the top four in terms of total defense), not one ranked worst than 29th in the nation in sacks (Alabama 29th). Notre Dame was able to hurry opposing quarterbacks, but it was tied for 59th in sacks with seven other schools (that was after coming on strong late in the season).
With the Irish pass defense a question mark in 2012, an improved pass-rush will help team by allowing for less coverage time.
Blitzing linebackers and defensive backs will also free up the defensive line, giving natural pass-rushers like Lynch and Tuitt more opportunities at the quarterback.
As one can see by the numbers, the Irish don't need a radical change in their defensive philosophy. Diaco just needs to tweak the game plan a bit on occasion.