To address the many posts that players are the ones who make the difference and the coach doesn't have that much effect. I think this year shows that Belichick can affect wins and losses than a lot of people say. The Patriots' defense has become so dominant, not just because the talent on the field, but because the Belichicks and Mayo retooled the defense to play to the talent they had's strengths and put them in the best position to win. A lot of coaches would probably just kept running their same defense and try to get the players to excel in it. Many coaches are very inflexible that way.
I think this defense could be a good to great defense without their current coaching based on the talent, but they are dominant defense because of Belichick.