I wrote an analysis of Oklahoma State's chances of passing Alabama for the #2 spot in the BCS last week and gave them two ways to accomplish it. They needed a loss by Alabama or the voters to decide they didn't want to see a rematch. Clearly the former didn't happen, and despite some oddities in the AP poll voting, we didn't see a mass change of votes in the coaches or Harris polls as Oklahoma State is still 5th in both.
All of the analysis and pundits are now saying an LSU vs Alabama rematch is inevitable, and I don't disagree, but it is still worth taking a look at what it would take for Oklahoma State to get to #2.
First, they need to win against Oklahoma. A win would likely get them some of the #2 spots back that they lost in the BCS computers to Alabama. I expect that a win would cement their #2 with the 2 computers that kept them there, and 3 of the other 4 computers would likely move them to #2. This would have them #2 in 5 of the 6 computers, and after you throw out the high and low, they would get the full 0.960 vs 0.920 margin, or 0.04.
Second, should Georgia somehow beat LSU, that might hurt Alabama in a few of the computers increasing the chances they move ahead of Alabama in all of the computers. Further, there is a slight chance that an LSU loss could drop them behind Oklahoma State in 1 or 2 computers which might increase their computer number to 0.970 or a margin of 0.05. For what it's worth, if LSU were to lose and Oklahoma State win, they would move to #1 in my BCS algorithm and LSU would be #2.
That margin of 0.05 then has to be not lost in the polls. Effectively, they can give up no more than 0.025 in each poll, or 71 votes in the Harris poll and 36 in the coaches poll. They are presently 342 and 166 votes back respectively, so they have ground to make up. This leads us to the third item they need.
Third, they need Virginia Tech to lose to Clemson, or at least have a close win that convinces the voters that had Oklahoma State behind them to swap things. This could help significantly to make up the ground and eliminate another 1-loss contender.
Fourth, they need to not only win against Oklahoma, but do so in a convincing fashion that causes the voters to move them ahead of Stanford and Virginia Tech. With 115 voters in the Harris poll, to be 71 or fewer back, they'd have to be #2 or #3 on all ballots, and #2 on at least 22. With 59 voters in the coaches poll, they'd have to be #2 or #3 on all ballots, and #2 on at least 14.
Fifth, again, an LSU loss to Georgia could help in the polls as it would possibly get them a few #1 votes increasing the chance of maintaining the 0.05 gap they'd have with the computers.
There you have it. Is any of this likely? The win over OU certain has a good chance of occurring, but that may be about it. OU is not going to roll over so that game could be close negating the 4th point above, and it is pretty unlikely that LSU loses to Georgia which negates the 2nd and 5th points. And while Clemson beat Virginia Tech earlier this year, beating a team twice is no easy task so the 3rd point may not happen either.
So it is hard to imagine it happening as it would depend on a pretty significant change of opinion with the voters and while that may happen sporadically with some voters, I doubt it will happen to the degree necessary to pull it off.