To answer that question I looked over the remaining schedules of the ten teams, and then ranked them here on the basis of mainly there remaining schedules listed below. At least three of the undefeated teams are certain to lose, as six teams on the list must play at least one more game against an undefeated foe.
The two ACC teams and the two Big 12 teams still undefeated play regular season conference games vs one another, and the two SEC teams still undefeated will play each other in the SEC championship game if both get that far undefeated.
Undefeated BCS college football teams most likely to stay undefeated in 2013
1. Northern Illinois - 13-24 (.351)
Having already defeated the two Big Ten teams on its schedule this season, Northern Illinois has the easiest road to an undefeated season of the ten remaining undefeated teams. Ball State (7-1) will be the biggest threat, but the game is home for Northern Illinois. The Toledo (4-3) game is on the road, but the other three opponents only have two wins among them.
2. Fresno State - 15-18 (.455)
I think Fresno State is clearly the weakest of the undefeated teams left, but the Bulldogs have a pretty easy road to an undefeated season. The only winning team left on the schedule is Wyoming (4-3). The biggest threat will be playing the first ever Mountain West Conference championship game against either Boise State or Utah State.
3. Ohio State - 17-16 (.515)
Ohio State has to get past Penn State (4-2) at home and Michigan (6-1) on the road for a second consecutive undefeated season. Purdue, Illinois and Indiana pose no real threat. Then the Buckeyes have to win the Big Ten championship game. Not that tough a road.
4. Florida State - 21-19 (.525)
Undefeated conference foe Miami and a Florida Gators team that is offensively challenged are all that really stand between Florida State and undefeated regular season. If Florida State wins out, I think they will beat Virginia Tech or Miami in the conference championship game, and maybe play for the national title. Will it happen? IDK, but the road is not that tough.
5. Missouri - 19-15 (.449)
Maty Mauk will become a legend if he can keep Missouri undefeated this season. The Tigers still have to play South Carolina, Tennessee, Ole Miss, and Texas A&M, plus walkover Kentucky. Then Missouri would have to play and win the SEC championship game. All very unlikely.
6. Miami - 27-13 (.675)
Miami has Wake Forest, Florida State, Virginia Tech, Duke, Virginia and Pitt left on the schedule. Virginia is the only team with a losing record. Al Golden is doing a great job, but he needs a better quarterback to win out.
7. Alabama - 24-11 (.686)
Alabama has Tennessee, LSU, Mississippi State, Chattanooga, and Auburn left on the schedule. After Tennessee and Auburn pulled off big upsets last week, that schedule looks a little tougher now.
LSU still remains the biggest threat, but the game is in Tuscaloosa. Alabama and Missouri can meet undefeated in the SEC championship game, but Bama would be heavily favored if that happened.
8. Texas Tech - 23-8 (.742)
Texas Tech is the quietest of the undefeated teams left. The Red Raiders have Oklahoma, Oklahoma State, Kansas State, Baylor and Texas left on the schedule. Texas Tech is very unlikely to run that table unscathed.
T-9. Baylor - 25-8 (.758)
Baylor is averaging 64.7 points per game, but the only team they beat with a winning record is Buffalo. The Bears have Kansas, Oklahoma, Texas Tech, Oklahoma State, TCU, and Texas left on the schedule. One more fun week and then the season really begins for Baylor.
T-9. Oregon - 25-8 (.758)
Like Baylor, Oregon has whipped it up vs a light schedule, but they did easily beat Tennessee. Now the season begins though, as Oregon plays UCLA, Stanford, Utah, Arizona and Oregon State. That schedule is good enough to put Oregon into the national championship game if they win out.