After four weeks, we are down to 29 undefeated FBS teams. Some are unbeaten because they have handled tough teams and looked great in doing so; most just haven't played anybody yet.

So which ones should we take seriously? Instead of using advanced stats, we're going to go in the opposite direction to get a read on each of the 29 undefeateds. Let's create a rudimentary scoring system; we'll grade each team's performance (in each game) based on whether it was bad, okay, good, or very good (and came against bad, okay, good, or very good competition). This is the opposite of official, but let's see what these grades can tell us.

Click here to skip straight to the rankings.

AAC

Houston (3-0)

Good against bad (Southern U., 62-13)

Okay against bad (Temple, 22-13)

Okay against okay (Rice, 31-26)

The Cougars have certainly taken care of business, but they've really only looked like even a top-30 or -40 team once. One cannot imagine them surviving the next four games (at UTSA, Memphis, BYU, at Rutgers) still unscathed. Still, Houston's halfway to bowl eligibility after a season away from the postseason. That's something.

Louisville (4-0)

Very good against okay (Ohio, 49-7)

Good against bad (Eastern Kentucky, 44-7)

Good against okay (Kentucky, 27-13)

Very good against bad (FIU, 72-0)

Louisville has passed the tests it's been given, weak as those tests have been. The remaining road slate -- Temple, USF, UConn, Cincinnati -- looks infinitely easier now that Cincinnati has looked disappointing and USF has looked ridiculously bad, but we already knew that it was going to take an upset to keep the Cardinals from finishing undefeated. Rutgers and UCF at home are no sure things, and Cincinnati could still surprise (Tommy Tuberville lives for beating top-five teams), but so far Louisville's results have gone exactly as the Cardinals hoped and expected.

UCF (3-0)

Good against bad (Akron, 38-7)

Good against bad (FIU, 38-0)

Good against good (Penn State, 34-31)

You could easily give UCF a "very good" for the win at Penn State. That was a lovely win, and at this stage I think it's pretty clear that two Knights -- UCF and Rutgers -- are the clear second tier of the AAC. UCF's just good enough that I would seriously consider picking the Knights over Louisville if the game were in Orlando. But it's not.

ACC

Clemson (3-0)

Very good against very good (Georgia, 38-35)

Good against bad (S.C. State, 52-13)

Good against good (N.C. State, 26-14)

Clemson showed strong resolve by absorbing some blows from N.C. State and handling its business anyway. But let's just say I don't feel any better about the Tigers' passing-downs offense and offensive line than I did before. N.C. State had Tajh Boyd harried and throwing off of his back foot (even more than normal) for much of the game. Again, you get points for handling your business, but that's two straight merely good performances. And again, one should expect more from the No. 3 team in the country.

Florida State (3-0)

Very good against good (Pitt, 41-13)

Very good against okay (Nevada, 62-7)

Very good against bad (Bethune-Cookman, 54-6)

It might be a stretch to call Pitt good, but it's not a stretch to say that FSU has looked the part of a 4.0 student so far. Not many teams have. The next two weeks -- at Boston College, Maryland at home -- should be mostly easy wins, but we should start to learn more about FSU's flaws in advance of the huge October 19 trip to Clemson.

Georgia Tech (3-0)

Very good against bad (Elon, 70-0)

Good against okay (Duke, 38-14)

Good against good (UNC, 28-20)

The Yellow Jackets obviously don't have the marquee win that Clemson has -- they won't get their shot at Georgia until the end of the year, and it probably won't go as well -- but they have handled their business. Winning by 24 points at Duke still says something, and after a slow start, Tech made most of the plays in the final three quarters against North Carolina. This is a good team. It isn't a great one, but it's a good one that has proven as much as some of the supposedly elite teams ranked ahead of it.

Maryland (4-0)

Good against bad (FIU, 43-10)

Good against bad (ODU, 47-10)

Okay against okay (UConn, 32-21)

Very good against okay (West Virginia, 37-0)

The second half against WVU was far from very good, but Maryland gets a pass because of the weather and the fact that the Terps were up 30-0 at halftime. This team has a very good offense and a defense that bails itself out with play-making ability. Like Georgia Tech, we're not going to necessarily give Maryland the benefit of the doubt, but the Terps have certainly played like a top-25 to -35 team so far.

Miami (3-0)

Good against bad (FAU, 34-6)

Good against good (Florida, 21-16)

Good against bad (Savannah State, 77-7)

Florida did the Hurricanes some serious favors, but there's no question that Miami has done what it needs to do. (And it's hard to look only good while winning by 70 points, but Savannah State is so bad that allowing points of any kind is a bit of a black mark.)

Big 12

Baylor (3-0)

Very good against bad (Wofford, 69-3)

Very good against bad (Buffalo, 70-13)

Very good against okay (ULM, 70-7)

Granted, the score of the ULM game should have probably been closer to 21-6 or something -- ULM went for it on fourth down in Baylor's red zone twice instead of kicking field goals (because field goals aren't going to beat Baylor), and Baylor was gifted two early pick sixes on mistakes by ULM receivers -- but that wouldn't have stopped the Bears from still cruising to about a 56-13 win. And they probably could have ended up with more yards if they had a reason to (i.e. if the game were closer for longer).

I still have obvious questions about the defense, which gave up too many early opportunities to Buffalo and allowed a couple to ULM as well, but that's picking nits at this point. Baylor's offense has somehow found another gear, and one has to consider the Bears one of the favorites to win the Big 12.

Oklahoma (3-0)

Good against okay (ULM, 34-0)

Okay against okay (WVU, 16-7)

Very good against okay (Tulsa, 51-20)

Clearly Bob Stoops and company saw something in Trevor Knight that allowed him to win the starting job over Blake Bell. But when Knight got hurt and Bell started in his place, OU transformed from "very good defense, shaky offense" to "very good across the board." That's one game, but we'll get a very good idea of how seriously to take the Sooners when they travel to South Bend this weekend.

Oklahoma State (3-0)

Good against good (Mississippi State, 21-3)

Good against okay (UTSA, 56-35)

Good against bad (Lamar, 59-3)

The running game looked sketchy against both UTSA and Lamar, but it didn't have to look better than that. The 'Pokes have passed the one true test they were given, and if they're a true Big 12 contender, they should get through the next four games (at WVU, Kansas State, TCU, at Iowa State) unscathed as well.

Texas Tech (4-0)

Good against okay (SMU, 41-23)

Good against bad (Stephen F. Austin, 61-13)

Good against good (TCU, 20-10)

Good against okay (Texas State, 33-7)

I defended the Big 12 quite a bit in the offseason, saying that there were as many as five potential top-15 teams at the top. Well, Texas clearly is not, and the loss of quarterback Casey Pachall has knocked TCU down a couple of pegs. But Baylor looks the part (far more than I even expected), and both Oklahoma and Oklahoma State still have clear top-15 potential, and Texas Tech has reached a decent cruising altitude. Tech probably isn't top-15 caliber, but the Red Raiders could be top-25. We'll know more if they can handle upcoming trips to Kansas and WVU without tripping up.

Big Ten

Michigan (4-0)

Very good against bad (CMU, 59-9)

Very good against very good (Notre Dame, 41-30)

Okay against bad (Akron, 28-24)

Okay against okay (UConn, 24-21)

Wait, Michigan's still undefeated? Are we sure? Because it kind of feels like they lost each of the last two games.

Minnesota (4-0)

Okay against bad (UNLV, 51-23)

Okay against bad (NMSU, 44-21)

Okay against bad (Western Illinois, 29-12)

Good against okay (San Jose State, 43-24)

Credit where it's due: San Jose State really could be a decent team, and Minnesota pulled away from the Spartans in the second half. The Gophers have mastered the art of the rope-a-dope against flimsy competition, looking near-awful in the first half before pulling away in the second. They aren't going to remain undefeated much longer (they are quite possibly inferior to each of their next eight opponents), but taking care of business early has gotten them two-thirds of the way to bowl eligibility. As with Houston, that's something.

Northwestern (4-0)

Good against okay (California, 44-30)

Very good against okay (Syracuse, 48-27)

Okay against bad (WMU, 38-17)

Okay against bad (Maine, 35-21)

I have no idea what to think of Northwestern right now. The Wildcats were spectacular early against Syracuse but have looked between decent and below average for most of the last five halves of football. Luckily, we won't have to wait long to find out what NU has to offer. After a bye week this Saturday, the Wildcats host Ohio State and visit Wisconsin. That will tell us what we need to know.

Ohio State (4-0)

Good against bad (Buffalo, 40-20)

Good against bad (San Diego State, 42-7)

Very good against okay (California, 52-34)

Very good against bad (Florida A&M, 76-0)

We learned on Saturday that Ohio State's fourth-stringers are better than Florida A&M. Glad we got that figured out.

Independent

Navy (2-0)

Good against okay (Indiana, 41-35)

Good against bad (Delaware, 51-7)

I mean, we're not talking about world-beaters here, but Navy's looked the part of a top-40 team thus far. Or at least top-50.

MAC

Northern Illinois (3-0)

Good against good (Iowa, 30-27)

Okay against bad (Idaho, 45-35)

Okay against bad (Eastern Illinois, 43-39)

If EIU had held onto its early 20-0 lead and knocked off NIU like it had already beaten San Diego State, the Panthers would have been granted immediate promotion into the MAC. It would have been for the best, really; UMass doesn't really want to be there anyway.

Mountain West

Fresno State (3-0)

Good against good (Rutgers, 52-51)

Okay against bad (Cal Poly, 41-25)

Good against good (Boise State, 41-40)

It really is a shame that Fresno State and Utah don't play each other this year (at least, not before bowl season); on alternating plays, those two teams look good enough to beat anybody and bad enough to lose to anybody. But FSU has now survived two good teams (and yes, I consider both Rutgers and Boise State good). That's more than a lot of undefeateds can say, even if both wins were by one point at home. And the Bulldogs are now better than every remaining opponent on the schedule, even if the advantages over road opponents like San Jose State and potentially San Diego State or Wyoming are not enormous. I expect them to lose at least one of those three games, but FSU certainly has a shot at running the table.

Pac-12

Arizona (3-0)

If we were to draw up the top 25 from scratch, No. 13 UCLA would potentially be sixth.

Good against bad (Northern Arizona, 35-0)

Very good against bad (UNLV, 58-13)

Good against okay (UTSA, 38-13)

The offense has looked good, the defense has looked good, and we'll know infinitely more after trips to Washington (this Saturday) and USC (October 10).

Colorado (2-0)

Good against okay (Colorado State, 41-27)

Okay against bad (Central Arkansas, 38-24)

No, there are probably not too many more wins on this schedule. But "The Buffs have taken care of business thus far" is not something we've been able to say much in the last decade or so.

Oregon (3-0)

Very good against bad (Nicholls State, 66-3)

Very good against okay (Virginia, 59-10)

Very good against okay (Tennessee, 59-14)

Nevermind the trip to Stanford on November 7 ... I cannot wait for Oregon at Washington on October 12.

Stanford (3-0)

Good against okay (SJSU, 34-13)

Good against bad (Army, 34-20)

Very good against good (Arizona State, 42-28)

Like Alabama, the Cardinal looked as good as they needed to look against mediocre (at best) teams to start the season; but in going up 39-7 on Arizona State (before the backups gave a lot back), I think they proved a lot.

UCLA (3-0)

Very good against okay (Nevada, 58-20)

Very good against good (Nebraska, 41-21)

Very good against bad (NMSU, 59-13)

I understand that you're supposed to beat NMSU by 46 points; but the Bruins have been explosive on offense and mostly stingy on defense, and if we were to draw up the top 25 from scratch, I think they'd potentially be sixth or seventh instead of 13th...

Washington (3-0)

Very good against good (Boise State, 38-6)

Good against okay (Illinois, 34-24)

Very good against bad (Idaho State, 56-0)

...and Washington would quite possibly be in the top 10 as well. I don't want to overstate things here -- killing Idaho State doesn't mean much, and as we get further removed from Illinois' random pasting of Cincinnati, we might be less impressed by the Huskies' 10-point win in Chicago. But that Boise State win scored serious points with me, and I'm leaning toward "Washington is legit" right now.

SEC

Alabama (3-0)

Very good against good (Virginia Tech, 35-10)

Very good against very good (Texas A&M, 49-42)

Good against okay (Colorado State, 31-6)

A) Yes, Alabama tends to hold something in reserve against lesser opponents and is less likely than peers to go out and win a game by 63 points.

B) Yes, previous Alabama national champions have had their lackluster performances. The Tide only beat a bad FAU team by 40-7 last year and struggled with Georgia Southern's option in a 45-21 win in 2011.

C) Still, the Tide barely gained 200 yards against Virginia Tech and led Colorado State by just a 17-6 margin heading into the fourth quarter on Saturday. Previous Alabama teams would have done more than that. I'm not changing my national title pick by any means, but I'm far less sold on the Tide than I was four weeks ago.

D) Yes, I'm being incredibly generous giving Alabama a "very good" for Virginia Tech. Too generous, probably.

LSU (4-0)

Very good against good (TCU, 37-27)

Very good against bad (UAB, 56-17)

Very good against bad (Kent, 45-13)

Very good against okay (Auburn, 35-21)

This is the best LSU offense since at least 2007. The defense still has some questions to answer, but thus far the Tigers have been the top-six to -eight team I expected them to be.

Missouri (3-0)

Good against bad (Murray State, 58-14)

Good against okay (Toledo, 38-23)

Good against okay (Indiana, 45-28)

The Toledo game probably should have been closer (Toledo blew some opportunities), and the Indiana game should have been even more lopsided (Missouri blew some opportunities). In all, though, this is a good team. We'll find out how good when the Tigers visit Vanderbilt in a couple of weeks (and then embark on an @Georgia-Florida-SC stretch).

Ole Miss (3-0)

Good against good (Vanderbilt, 39-35)

Okay against bad (SE Missouri State, 31-13)

Very good against good (Texas, 44-23)

The last impression is always the clearest, and Ole Miss looked awesome in the second half against Texas. The Rebels haven't looked that good all year, but obviously they'll get a chance to make a statement in Tuscaloosa on Saturday.

Okay, so what if we give out GPAs based on the grades above? Let's give four points for a "very good," three for "good," two for "okay," and one for "bad." How are teams grading out so far?

(Teams' AP rankings are listed below.)

4.0 average

No. 8 Florida State (vs. 2.0 competition)

No. 13 UCLA (vs. 2.0)

No. 6 LSU (vs. 1.8)

No. 2 Oregon (vs. 1.7)

No. 19 Baylor (vs. 1.3)

Forget your preconceptions for a moment; these five teams have looked the most consistently great so far this year. Granted, almost none of them have played anybody, but as I like to say, you can only pass the tests you've been given. The tests will get tougher for all involved soon enough.

3.7

No. 1 Alabama (vs. 3.0)

No. 16 Washington (vs. 2.0)

And this is only if you give Alabama a "very good" for the defensive (and non-offensive) performance against Virginia Tech. Nick Saban has some work to do, but he probably likes it that way.

3.5

No. 7 Louisville (vs. 1.5)

No. 4 Ohio State (vs. 1.3)

Good enough for the schedules at hand.

Seriously, can we redraw the schedules before Saturday? Obviously Wisconsin (in Columbus) and Northwestern (in Evanston) will be a pretty stiff 1-2 punch for Ohio State to handle, but that shouldn't be the stiffest test standing between you and the BCS title game. And what's Louisville's toughest 1-2 punch ... Rutgers-UCF, I guess? Yuck.

3.3

No. 3 Clemson (vs. 2.3)

No. 5 Stanford (vs. 2.0)

No. 27 Georgia Tech (vs. 2.0)

No. 32 Arizona (vs. 1.3)

Either Clemson and Stanford are overrated, or Georgia Tech and Arizona are underrated. Or, you know, neither. It's still early.

3.0

No. 21 Ole Miss (vs. 2.3)

No. 18 Michigan (vs. 2.0)

No. 14 Oklahoma (vs. 2.0)

No. 11 Oklahoma State (vs. 2.0)

No. 24 Texas Tech (vs. 2.0)

No. 15 Miami (vs. 1.7)

No. 29 UCF (vs. 1.7)

No. 35 Missouri (vs. 1.7)

No. 28 Maryland (vs. 1.5)

No. 36 Navy (vs. 1.5)

Michigan is No. 18 in the polls, and Baylor is No. 19.

I'm going to write that again. Michigan is No. 18 in the polls, and Baylor is No. 19. Just want to hammer that home.

Oh yeah, and Nebraska's still receiving more votes than Arizona.

2.7

No. 17 Northwestern (vs. 1.5)

No. 25 Fresno State (vs. 1.3)

These teams have high ceilings, it seems, but have not dominated lesser teams like you're supposed to.

2.5

Colorado (vs. 1.5)

2.3

No. 31 Northern Illinois (vs. 1.7)

Minnesota (vs. 1.3)

Houston (vs. 1.3)

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