On this week's episode of Bills by the Numbers presented by FanDuel, Chris Brown and Steve Tasker take a look at the team's defense through four games. They discuss what needs to be fixed, the top priorities as the season rolls on, and the impact of players returning from injury and suspension. They also looked ahead to the possible contributions from rookie CB Maxwell Hairston when he comes off of injured reserve. Steve is quizzed on Bills-Patriots history in The Numbers Game. Finally, the two give their answer to this week's One Burning Question - who should the Bills be worried about in the AFC race?