Week 4 saw the Colorado Buffaloes meet reality in the form of the Oregon Ducks and 12 previously undefeated teams lose.
Things don't get any easier for Colorado in Week 5 with the USC Trojans visiting Boulder. The Trojans, however, are still stuck with some lingering questions about their defense.
The Notre Dame Fighting Irish, who suffered their first loss last week, will try to bounce back quickly but have to face the undefeated Duke Blue Devils.
Can the Irish rally and keep their slim College Football Playoff chances alive?