Alabama’s defense was particularly impressive Saturday against LSU. (Gerald Herbert/Associated Press)

A Saturday of marquee games has brought the playoff picture into focus. While the leaders remain the same, the pack of chasers has thinned considerably. Long shots LSU, Kentucky and Texas each controlled its fate and each was effectively eliminated with losses on Saturday (with the Longhorns’ loss coming in excruciating fashion).

Our power ratings (how well we expect teams to play going forward) show the top teams in four distinct tiers. Here is our Top 20, with playoff probabilities attached where relevant (>1 percent):

Tier 1: Alabama (95 percent chance of making playoff), Clemson (97 percent)

Alabama and Clemson separated themselves even further from the pack, with the Nos. 1 and 2 performances of the weekend. Alabama-LSU was more one-sided than we expected; the surprise was how dominant Alabama’s defense was, holding LSU to only 108 yards through the first three quarters. If anything, Alabama should have won by more — our game grades showed the Tide more than 40 points better than the Tigers.

Clemson looked dominant (again) against a lesser opponent, rushing for 492 (!) yards against Louisville. How will that translate in a game against Alabama? The Westgate SuperBook makes the Tigers an 8.5-point underdog in a potential national championship game. We think the gap is considerably smaller; we’d only favor Alabama by 1.5 points. Such a potential matchup is still more than two months away, but it’s growing more likely by the week — we make it practically a coin flip.


Massey-Peabody

Tier 2: Michigan (58 percent), Georgia (36 percent), Oklahoma (45 percent)

Tier 2 is a tight cluster of very good teams within two points of each other but far behind the leaders. The best Tier 2 team (Michigan) would be an eight-point underdog against the lesser of the Tier 1 teams (Clemson). It’s astounding that is the best competition the other 128 teams can muster for the two runaway leaders, but that’s the story of the season.

The playoff paths for Georgia and Michigan are clear as can be: Win out and they’re virtual locks. Lose a game and, pending a perfect storm of chaos, they’re out.

The path is somewhat less clear for Oklahoma. We see the Sooners making the playoff 75 percent of the time if they win out. They would slot behind an undefeated Notre Dame (58 percent) or a 1-loss Michigan (49 percent), so if both those coin flips hit the Sooners are out of luck.


Massey-Peabody

How bullish you are on Oklahoma’s chances also depends on the merits of a one-loss Sooner team versus a one-loss Notre Dame and one-loss Ohio State. When all is said and done, Oklahoma will have played the toughest regular-season schedule of the three teams and is, by our numbers, the best of the group. But Ohio State would have a marquee win over Michigan, bringing it into a dead heat with Oklahoma according to our committee forecast. We think both Oklahoma and Ohio State would slot above Notre Dame, in this scenario.

Tier 3: Ohio State (18 percent)

There’s another big gap between Tiers 2 and 3. We’d make Ohio State a 6.5-point underdog against Oklahoma on a neutral field. Yet Ohio State controls its destiny more than Oklahoma does. A one-loss Ohio State has an 83 percent chance of getting in, not least because the Buckeyes winning out would necessarily mean the Wolverines don’t.

The problem for Ohio State is that it’s going to be quite difficult to win out. The Buckeyes struggled to beat 2-6 Nebraska at home on Saturday and they’re only a narrow favorite (60 percent) to win in East Lansing this weekend. They’ll be an underdog — we make the spread at 5.5 points — hosting Michigan on Nov. 24. Add in the Big Ten title game, and their chances of winning out slip to 1-in-5.

Tier 4: Mississippi State, Notre Dame (45 percent), Penn State, Texas A&M, Washington, Auburn, Missouri, LSU (3 percent), Utah

The only Tier 4 team in the conversation is Notre Dame. Yes, that’s right, Notre Dame is Tier 4. We even think three-loss Mississippi State is just as good! The Irish looked like an elite team in Weeks 4-6, when they blew out Wake Forest, Stanford, and Virginia Tech, registering Top-10 performances in each. They’ve struggled since against inferior opponents and failed to crack a Top-20 game grade.


Massey-Peabody

All that said, what matters most is wins and losses — there would be little debate about an undefeated Notre Dame. But, add a loss to the mix, and the Irish’s struggles with inferior teams could haunt them.

Tier 5: Wisconsin, West Virginia (2 percent), Michigan State, Texas, Miami

More the bottom of the queue than a real tier, there is still one team floating around down here with a chance: West Virginia. For now, anyway. We just don’t think it’s good enough to win out. It not only has to beat TCU and Oklahoma State, but also Oklahoma … TWICE. It could happen (4 percent chance) but we’re not banking on it. Even if the Mountaineers get in we don’t see them going far — they’d be a 23.5-point underdog against Alabama.

So we’re down to seven. Many would say two, but we’re not ready to go that far yet. We believe Michigan, Georgia and Oklahoma could put up respectable fights against the Big 2 and, with a few breaks, pull off upsets. We are less convinced about Ohio State, and are downright unconvinced about Notre Dame. If you’re pulling against a Crimson Tide coronation in January, you might want to pull against the Fighting Irish in November.


Massey-Peabody

Cade Massey (a Wharton professor) and Rufus Peabody (a professional sports bettor) are co-founders of Massey-Peabody Analytics, which produces proprietary quantitative college football ratings. Each week, they simulate the rest of the college football season and the playoff committee’s selection process 20,000 times and explore some of the most interesting outcomes.