The Bears' plan to improve their NFL-leading defense

When you’re the best defense in the NFL, can you get better? The Bears and their new defensive coordinator think so.

But with the NFL’s highest-paid defensive player and without a pick in the first two rounds of the draft (the rounds in which they procured four starters over the last five drafts), the opportunities for the exponential leap that came with the trade for Khalil Mack and the selection of Roquan Smith last offseason are next to nil.

Still, “our vision for this defense is to be the best,” said Chuck Pagano upon arrival to succeed Vic Fangio as defensive coordinator. “Can we be the best in the history of the game? The pieces are there and they will continue to add pieces. Can we…