Our Tigers have run a 4-3 defense for quite a long time, meaning they line up with 4 defensive linemen and 3 linebackers.  In this kind of scheme, your defensive linemen have to be quick and athletic to make up for the speed lost by taking out a linebacker and adding a defensive tackle.  You need depth at tackle in order to do this, as you will need probably 5 or 6 tackles to get through a season, and that's only if you don't have a rash of injuries.  

Take a look at LSU's roster.  There are only 3 experienced defensive tackles listed:  Charles Alexander, Drake Nevis, and Al Woods.  Two of those guys are seniors.  If you look at the Class of 2009, which we have been doing, you see two more defensive tackles, Chris Davenport and Josh Downs, with JUCO transfer Akiem Hicks being a hybrid DE/DT.  If you look at the commitment list for the Class of 2010, which currently has 21 commitments, you will see we have zero defensive tackles committed to the 2010 class.  If you do the math factoring in the guys we KNOW we want like Trovon Reed and Lache Seastrunk, you wonder if there is going to be any defensive tackle signed.

This makes for a situation that appears, at least at first blush, to give us a very thin depth chart at defensive tackle for 2009, and an even thinner depth chart in 2010.  This has been caused by attrition (Sidell Corley transferring, Ricky Jean-Francois going to the NFL early), position switches (Cordian Hagans switching to offensive guard) and graduation (Marlon Favorite).

At the same time, you can look at how we've recruited linebackers and see that we are stocking up.  Barkevious Mingo, Kevin Minter, Tahj Jones, and Lamin Barrow were all a part of the Class of 2009, while Rockey Duplessis greyshirted from the Class of 2008.  Josh Johns could also end up at linebacker.  In the Class of 2010, we have added Luke Muncie, DJ Welter, and Justin Maclin, while either Sam Gibson or Houston Bates could eventually end up there as well.  That is a huge linebacker haul in terms of numbers in a short period of time, while at the same time our defensive tackle recruiting has slowed down a lot.

All of this comes while the 4-3 defense is being phased out at some other places.  The NFL, which not that long ago was composed mostly of 4-3 defenses (popularized by Buddy Ryan in the 1980s), appears to be returning to the pre-Buddy Ryan days of more 3-4 defenses.  At Bama, Nick Saban (who ran an unabashed 4-3 system just a few years ago at LSU) quickly converted Bama from a 4-3 to a 3-4.  This trend appears to be the defenses' counter to the fact that offenses are moving more towards a wide open, field-spreading attack (even teams that aren't in the "spread" are still trying to stretch the defense more by passing more often than they did a few years ago).  Teams are responding by getting more linebackers on the field at the expense of hulking defensive tackles. 

This brings up the question.  With fewer defensive tackles and more linebackers, are we setting up a switch to the 3-4?

I don't have a definitive answer to that question.  After all, positions can be somewhat fluid.  While Davenport and Downs are definitely tackles, Bennie Logan and/or Michael Brockers may be as well, though I have considered them defensive ends to this point.  Michael Brockers in particular has bulked up quite a bit, as he now is listed at 285#, and reports say he looks it.  Class of 2008 signees Lavar Edwards and Chancey Aghayere, who have previously been considered defensive ends, may also see a move to tackle.  Lavar Edwards, a redshirt freshman, is actually now listed as a tackle.

Or will these guys just be the kind of big defensive ends that the 3-4 system requires?

I'm not saying it's happening, and I'm not taking a position on whether it should happen.  The circumstances have simply made me suspicious about our plans for the future of the defensive tackle position.