As good as Urlacher is, he is not the Bears' best defensive player. He is very important to their defense, but I feel that he is mroe replaceable than Polamalu. Polamalu is all over the field making plays. He will make plays in the box, then turn around and make an acrobatic pick and take it back for 6. He is an incredibly dynamic player who will be greatly missed by the Steelers. My guess is that this helps the Bears' passing game enough for them to win it, as long as Cutler has time to throw.