This year, it appears that CBS made a mistake.
Each year, the network gets to pick one CBS game to move out of the 3:30 PM Eastern Time slot and shift into prime time. And every year from 2011 to 2018, that game was LSU vs. Alabama. In that eight-year span, there were three games with both teams ranked in the top five, and two more when both were in the top ten.
But this year, CBS chose to flex out Georgia-Notre Dame instead, as the week four game featured a #3 vs. #7 matchup, won by Georgia 23-17.