I try not to think in terms of reversion to the mean much. Because up isn't the only way to go. In theory, it can always get worse. Or stay the same. That might be harder to comprehend than getting worse.
In 2010, the Dawgs were a middle of the road defensive team. They ranked 36th in scoring (5th in the conference), 23th in total defense (4th in the conference), and were in the upper 40s and mid 50s in sacks and tackles for loss. However, we were bad at stopping the run. Georgia was an embarrassing 56th in the country and 7th in the conference, giving up just under 150ypg on the ground.
Red zone conversion defense was even worse. Teams scored TDs nearly 75% of the time they got inside the red zone. Good for 107th in the nation, with the likes of Washington, Minnesota and Utah State. Georgia gave up 22 rushing touchdowns from inside the red zone. They only gave up four passing TDs inside the red zone, but opponents only attempted 24 passes all season from inside the 20. For comparison sake, that is tied for 2nd in the nation for the fewest pass attempts by opponents in the red zone and is 13 fewer than Mississippi faced as the next lowest in the conference. Teams decided that they didn't need to pass to open up the run when they got close, in effect saying we will man handle you up front. And manhandle us, they did.
Most telling is that teams only had to settle for field goals 4 times out of 38 red zone possessions. Fortunately, Georgia only allowed 38 red zone possessions, good for top 20 in the nation. That is how we were as strong as we were in scoring defense.
No one thought the conversion from 4-3 to 3-4 would be painless. I don't think anyone would have thought our rushing defense would look like UABs, either. We get 23 returning starts from the projected starting linebackers. Add in Jarvis Jones, provided he is eligible, and I like that starting group. As for the front three, it is imperative John Jenkins is all that and a bag of chips. By all accounts, he is. Putting Kwame and Jenkins on the line together at times will create some very advantageous match ups. That also gives the other end and any OLB that we bring up to the line the opportunity to wreck havoc in offensive back fields.
One other thing that strikes me is that we didn't bring as much pressure from the front seven last season as I thought we would under Grantham. I don't know if that was situational or intentional, but with another year of study and practice, plus having a couple of key players that fit the 3-4 better makes me think we'll see more stunting and blitzing up front. Last season, Georgia had trouble handling the most basic thing a defensive player has to do: protecting their territory. We got whipped on the line of scrimmage and got caught not covering basic run plays.
Stop getting whipped and protect the basic run plays, and Georgia's rushing defense and red zone TDs allowed goes back to merely average, resulting in about 3 fewer points per game allowed. That would put us at 20ppg, good for top 25 in the nation or so in each of the past five seasons. Do both of those and significantly improve tackles for losses (thus taking some pressure off the secondary) and Georgia should be solid on the defensive front.