The last weekend of September has arrived, and the playoff picture looks largely the same as it did a month ago, even as the teams at the top have survived injuries, upset bids and a few quarterback changes along the way. Week 5 brings the season’s first true heavyweight bouts since Week 1, when no one knew what to make of Auburn’s win over Washington or Notre Dame’s win over Michigan. It will still be too early to draw sweeping conclusions from what happens in State College and South Bend on Saturday night, but with the year’s first official College Football Playoff rankings roughly a month away, the time is now for separating the true contenders from the solid teams a rung below the elite.