Modern NFL makes it harder for D to lead way to title

FILE - In this Dec. 23, 2018, file photo, San Francisco 49ers quarterback Nick Mullens (4) is hit by Chicago Bears defensive end Akiem Hicks, left, and outside linebacker Khalil Mack during the second half of an NFL football game in Santa Clara, Calif. An already strong Bears defense got only better with the acquisition of elite pass rusher Mack before the season. With Mack and Akiem Hicks wreaking havoc up front and Eddie Jackson and Kyle Fuller providing big plays from the secondary, the Bears allowed the fewest points in the NFL this season and appear to have the defense best equipped for a long postseason run starting with Sunday's home game against defending champion Philadelphia. (AP Photo/D. Ross Cameron, File)

From Pittsburgh’s Steel Curtain in the 1970s to Chicago’s Monsters of the Midway in the ’80s to Seattle’s Legion of Boom more recently, dominant defenses have often been the story of the NFL postseason.