There are compelling reasons to go back to a 3-4 defensive front seven, i.e. one having Defensive Ends flanking a Nose Tackle at the LOS and, a 2nd row of 2 outside linebackers and 2 inside linebackers.
Oakland used the 3-4 set successfully from 1976 through 1989, winning 62% of the games. By contrast, since converting to a 4-3 Defensive (2 DTs, 2DEs, 2 OLBs and 1 MLB) we have won only 52% of our games. Incidentally, in all three of our SB Championship victories and the seasons leading up to those Super Bowls, we used the 3-4 defense.
While no one will attribute our successes or failure solely to the configuration of the front 7, the use of our personnel's talent is a major factor to the results in the record book. Therefore, after considering our current player strengths and weaknesses and the inherent advantages of the 3-4 Defense scheme, the benefits of reinstalling the 3-4 should be clear.
Consider our DE strength: Greg Ellis, Matt Shaughnessy, Jay Richardson and Rich Seymour. Ellis played OLB at Dallas very successfully and Richardson and Seymour are prototype DEs in the 3-4 scheme, stalwart and quick - if not fast.
Consider our DT weakness: though sometimes terrific Gerard Warren lacks consistency and Tommy Kelly can't be described any better. Desmond Bryant is developing w/ promise. These DTs are quick but not huge and have been pushed around in the interior on too many occasions. But they might work out as DEs in a 3-4 set.
Now consider our LB strength and weakness: Thomas Howard and Trevor Scott on the outsides are doing a great job; our "MLB", Kirk Morrison is a sure but soft tackler who isn't a true MLB (can't intimidate or direct play) but either a misplaced ILB in a 4-3 set or, more likely, a 3-4 OLB forced to play Middle by default in a 4-3 scheme. Our Linebackers are fast and more suited to the 3-4 scheme that sends them against QBs just as the 4-3 sends DEs.
Finally consider that DC, John Marshall, knows the 3-4; he helped install it in S.F. when they converted to it in '07.
All things considered, if we were to install the 3-4 today it would look much like this:
RDE - Gerard Warren / Jay Richardson
LDE - Rich Seymour / Matt Shaughnessy
ROLB - Trevor Scott / Sam Williams
LOLB - Greg Ellis / Slade Norris
RILB - Thomas Howard / Ricky Brown
LILB - Kirk Morrison / Jon Alston
NT - Tommy Kelly / Desmond Bryant
SS - Tyvon Branch / Mike Mitchell
FS - Michael Huff / Hiram Eugene
RCB - Nnamdi Asomugha / Jonathan Holland
LCB - Chris Johnson / _____________
A 3-4 we will only require a stud Nose Tackle by way of draft or FA and probably another ILB, e.g. Alabama's Rolando McClain, Missouri's Sean Wheatherspoon, or Iowa's A.J. Edds. We should be able to get one of those three and that only leaves us with the Yokozuna NT. The advantage of converting now are especially appealing because we really need to upgrade the Offensive line to give our excellent running backs and Bruce Gradkowski every opportunity to show this league how excellent they really are.
Discussions of who that Nose Tackle cornerstone should be and your thoughts about returning to the 3-4 are now open for discussion.