Most would agree that #21 is the premier shut-down corner in the NFL. Nevertheless, he is not generating big plays, i.e. interceptions. Could it be that Asomugha's prime directive is misplaced? Could his concept of his place in the game be faulty?
It's well known that Hayes and Haynes intentionally baited QBs; they aggressively worked for interceptions by trying to make QBs throw their way. To achieve that, they feigned imperfect coverage to lure the pass - which they both considered as meant (fated) for their very own hands. I don't see this trait / ability / mindset (call it whatever you choose) with Nnamdi, whose focus is only to blanket the receiver and, apparently, prevent the QB from even considering throwing it his way.
As good a CB as Nnamdi Aomugha is, and he is also the best tackler on the team, he is not in the same category with Willie Brown, Mike Haynes and Lester Hayes because he lacks their mentality of wanting the ball and their special skill of luring passes their way in order to take possession for their team. The great Raider CBs changed the outcomes of games they played in with big plays on a regular basis whereas, by comparison, Nnamdi prevents 'his guy' from catching the ball.
Compare these Raider CBs' metrics:
Willie Brown, [4 years w/Denver] 12 years a Raider - 1967-78. In his 114 games as a Raider, Willie had 39 interceptions - 2 TDs, 9 Pro Bowls [HOF]
Mike Haynes, [7 years w/NE] 7 years a Raider - 1983-89. In his 87 games as a Raider, Mike had 17 interceptions - 1 TD, 9 Pro Bowls [HOF]
Lester Hayes, 10 years a Raider -1977-86, 149 games - 39 interceptions - 4 TDs, 5 Pro Bowls [Finalist or Semi-finalist 9 times in HOF balloting]
Terry McDaniel, 10 years a Raider - 1988-97, 143 games - 34 interceptions - 5 TDs, 5 Pro Bowls
Nnamdi Asomugha, 8 years a Raider -2003-10, 119 games - 11 interceptions - 1 TD, 4 Pro Bowls
Despite Asomugha's cover skills (and excellent tackling) the Raiders secondary gave up 65 touchdown passes over the past 3 years. During the same period Nnamdi had 2 interceptions. Moreover, as Jerry McDonald pointed out, in the 3 games Nnamdi missed, Oakland won 2 out of 3.
Is Asomugha worth $16 million / year to the Raiders? Absolutely not; and given the likelihood of a roster salary cap in 2011 of approx. $125 million, Oakland would be making a drastic mistake spending seven (7) times the average player salary on this single-cover specialist.