Defenders Donald, Mack anomalies in an 'offense-first' league

LOS ANGELES_The NFL is built for scoring. Rules favor quarterbacks and receivers. Records are rewritten every week. A team scores 51 points ... and loses to a team that scores 54.

But in a league dominated by O, the biggest game this weekend will be decided by the X factor.

Make that two bolded, underlined, highlighted Xs - a pair of defensive stars who have played their way into the most-valuable-player conversation.

Defensive tackle Aaron Donald of the Los Angeles Rams and outside linebacker Khalil Mack of the Chicago Bears will be on opposite sides of a pivotal NFC game on Sunday night, a matchup so compelling it was flexed into the national prime-time slot.

This season, nobody flexes like Donald and Mack, who play different positions on