The field always winnows itself down. Two more unbeaten college football teams lost this week, and now we're down to three: Ohio State, LSU and Clemson.

Since four teams make the College Football Playoff, however, that means our time for arguing about résumés and who would beat whom and who ain't played nobody has just begun. The SP+ ratings have been updated through Week 12, and here's what they have to say about the pool of one-loss teams currently vying for the fourth spot in the CFP (assuming no more unbeatens lose*).

One-loss power conference teams and their SP+ rankings: 2. Alabama; 5. Georgia; 6. Oklahoma; 7. Penn State; 8. Utah; 15. Oregon; 16. Minnesota; 21. Baylor.

Admittedly, Alabama's place on this list is a bit blurry because of quarterback Tua Tagovailoa's season-ending injury. SP+ does not take injuries into account, but if Tua was worth an extra three to five points per game for the Tide, his absence drops them back to Georgia's range.

Still, they'd probably be projected favorites over most of this one-loss field. And it will be fascinating to see how much the CFP committee takes that into account moving forward. The Tide won't be a conference champion like a one-loss Utah/Oregon or Oklahoma/Baylor, but even without Tagovailoa they would probably be a projected favorite, per both SP+ and Vegas, against those teams. And since the committee swears it's choosing the BEST teams, not the MOST DESERVING ... well ... let's just say the arguing has just begun.

* SP+ gives Clemson an 87% chance of getting to 12-0, LSU a 78% chance, and Ohio State a 61% chance. Those are all good odds, but that means that there's only a 41% chance (0.87 x 0.78 x 0.61) that all three get there. There's a chance things only get blurrier from here.

What is SP+? In a single sentence, it's a tempo- and opponent-adjusted measure of college football efficiency. I created the system at Football Outsiders in 2008, and as my experience with both college football and its stats has grown, I have made quite a few tweaks to the system. SP+ is intended to be predictive and forward-facing. That is important to remember. It is not a résumé ranking that gives credit for big wins or particularly brave scheduling -- no good predictive system is. It is simply a measure of the most sustainable and predictable aspects of football. If you're lucky or unimpressive in a win, your rating will probably fall. If you're strong and unlucky in a loss, it will probably rise.