Originally posted by WildBill:
In defending the against the pass, BOTH are important. If you have a pass rusher that can get to the QB then the QB will be either sacked or forced to throw a bad pass that either goes incomplete or gets intercepted.
A shut down corner, can cause the QB to hold the ball longer than we wants which may lead to a sack, the ball being thrown away or an interception. It also allows you to double others or blitz more people which again leads to the above.
The key is which one can also better suppport the against the run when the otherside isn't passing. I just want Patrick Willis type of player at either of the position.
You don't have that choice because we don't need an ILB. To answer your question, a CB that can blanket a receiver helps against the run more. You are allowed to bring 8 in the box to rush the passer or play the run. With a weak CB, you must help in coverage using only 7 in the box and two of those 7 being "pass rushers" which would make you susceptible to the run.
This is why you still need both, but one allows you to do a lot more.
Scenario 1: Let's say you have a premier pass rusher combined with Clements and Spencer. How many times will that rusher create pressure? Not often, which means they can still hit us deep.
Scenario 2: Let's say we have a cover corner with the front 7 we have now. How many times do you think that CB will be beat deep? Not very often.
There is a higher probability to allow big plays with weaker DB's than there would be with a weak pass rush.