COLUMBUS, Ohio -- What has to go right? Basically, everything.

Any doubts about the difficulty of an undefeated season -- and it has only happened five times in 122 Ohio State seasons (1916, 1944, 1954, 1968 and 2002) -- were reaffirmed with losses by both Alabama and Louisville on Saturday.

But don't stop with the Crimson Tide and Cardinals. Ask any of the one-loss teams how this happened.

Florida State lost to 6-4 North Carolina State.

Florida beat LSU, Texas A&M and South Carolina, but couldn't hold on to the ball in a 17-9 loss to Georgia.

The Bulldogs managed that win, but were obliterated by South Carolina.

Even Kent State could be staring down an undefeated shot if not for a loss that served as Kentucky's only win.

It's hard. So how did Ohio State get here? With Wisconsin and Michigan remaining, and a tie for first in the Leaders Division already assured, here are 10 reasons the Buckeyes remain undefeated, one for each win.

1. The conference: Like it or not, admit that the No. 1 thing on the Buckeyes' side is their conference. Their shallow, questionable, mockable conference. It's not just what you are, but where you play.

The Big Ten is part of the reason the Buckeyes are 10-0 and almost entirely the reason that perfect mark has them at only No. 6 in the Associated Press poll, behind two one-loss teams in Alabama and Georgia.

The Buckeyes played games that were there for the taking -- including losing the turnover battle by three to both Michigan State and Purdue -- but their Big Ten foes haven't been able to take them. After Alabama's loss to Texas A&M on Saturday, coach Nick Saban said he thought his Crimson Tide were a little out of gas after the previous week's comeback road win at LSU.

There's nothing in the Big Ten that could compare to a back-to-back like that: at LSU against that defense, then coming home to face Texas A&M freshman quarterback Johnny Manziel.

And check out Oregon's three-game, season-ending stretch of Stanford, Oregon State and the Pac-12 title game. Nothing like that in the Big Ten, either.

Besides not having another great team after Ohio State, the Big Ten also isn't competent enough week in and week out to make a good team pay for a down week. If the Buckeyes had played games like they did in consecutive weeks against Indiana and Purdue in the Southeastern Conference, Pac-12 or Big 12, they would have been less likely to hold on for a three-point win and then escape with an overtime victory. Somebody would have taken a game from them. But not in the Big Ten.

2. The coach: Urban Meyer improved Bowling Green by six wins in his first season there, Utah by five, and Florida by two. The Buckeyes won six games last season, but beyond their quarterback issues, had talent more like an eight- or nine-win team. Attitude, inspiration, offensive ingenuity -- Meyer won't establish his program until he has the time for his recruiting to really shape the roster. But the coach has proven to be worth a couple of extra wins right off the bat. He's not for everyone. But he snaps guys to attention, so his turnarounds don't take long.

3. The quarterback: Put it this way: If Braxton Miller had played against Ohio State this season, he probably would have beaten the Buckeyes. He has the most 10-yard, 20-yard, 30-yard, 50-yard and 60-yard runs in the conference. (He's third in 40-yarders). Game in doubt? Always take the team with a player whose mere presence on the field is a play call. And a good one. Go Braxton. Do your thing.

4. The nonconference schedule: In the previous 10 years, Ohio State's nonconference schedule included No. 10 Washington State, No. 17 Washington, No. 24 North Carolina State, No. 2 Texas (twice), No. 1 Southern Cal, No. 3 Southern Cal and No. 12 Miami. In the next 10 years, it will include, among others, Virginia Tech, Cincinnati, Oklahoma, North Carolina, TCU, Oregon, Boston College and Texas.

California, now 3-8, as the featured nonconference opponent? For this season, the Buckeyes will take that tense, seven-point home win over the Golden Bears as a gift from the schedule gods.

5. The Big Hank: The Buckeyes have the 16th-best run defense in the country. The best two overall defenses that Ohio State faced were Michigan State and Penn State. But both of those teams featured offenses that insisted on trying to run on the Buckeyes. It wasn't a winning combination.

That doesn't work against Ohio State, especially not up the middle. The Spartans and Nittany Lions combined for 66 rush yards while averaging 0.8 yards per carry. Consider this a reminder of the existence of future top-10 NFL Draft pick Johnathan Hankins on a defensive line dedicated to them.

6. The cornerbacks: Bradley Roby leads the nation in pass breakups and Meyer praised Travis Howard last week for having a "fantastic" year. After early struggles with finding the right defensive plan of attack, Meyer and defensive coordinator Luke Fickell seemed to have settled on more man-to-man coverage and frequent blitzes. You can't do that unless you trust your cornerbacks.

7. The offensive coordinator: Ohio State is getting outscored, 62-58, in the first quarter. But how often have you said, "Why is Ohio State STILL doing this ineffective offensive thing?" Not often. Offensive coordinator Tom Herman and Meyer find the problems and fix them. Adjustments work. The slow starts aren't ideal, but the Buckeyes are winning the second quarter, 132-37.

8. The running back: Cal decided to try to stop the run in the third game of the season. It worked. Miller was limited to 75 yards on 12 carries, most of that on one big play, while Carlos Hyde was out with a sprained knee ligament. Guess what? Selling out to stop Miller on the ground doesn't work anymore. Hyde has 579 rushing yards and 11 rushing touchdowns in his last five games.

9. The opposing kickers: Cal went 0-3 on makeable tries in the 40-yard range in a seven-point loss, Michigan State was 3-of-4 on field goals but did miss a 42-yarder in a one-point loss, and Purdue had a 34-yarder blocked by Hankins and missed a 52-yarder in a game that went to overtime. The Penn State kicking situation has been so desperate all year, it completely changes the Nittany Lions' thinking on even trying field goals. Bottom line, face a decent kicker at the wrong time and a loss could have happened easily.

10. The thing that you can't put your finger on: Some might put this first. To me, that discredits the clear difference that the coaches and the players have made. It's not just want-to. It's turning practice into play, it's both implementing and accepting a new plan, it's a lot of tangible football skill and strategy.

And then there was the Kenny Guiton comeback against Purdue. In those games, there's a little pixie dust mixed with the sweat.

"I see some of the intangible locker room conversations and I see a special team," Meyer said recently. "They're fighting for each other. It's a refuse-to-lose type atmosphere. Some of us have seen teams that play really well, and they're blowing teams out all the time.

"We're not that type of team [and] I can give you 150 reasons why. However, we're a bunch of guys that work really hard, blue-collar approach, that show up every Tuesday [for practice] and want to get better. You don't want anything else as a coach."