I wrote up some observations of the week 9 BCS ratings yesterday including some scenarios on who might make it to the championship game. The latter garnered some good discussion on Twitter centered around what scenario would be required, or if there was one, that would get Boise State in. I thought it deserved its own analysis so here goes.
The simple view on who gets to the championship game looks at the order of the BCS rankings and handicaps the teams in order. Using this, assuming no unexpected losses, the LSU/Alabama winner is in the championship game, Oklahoma State is the first in line to meet them, Stanford is next should the Cowboys slip up, and Boise State would be next if both have a loss. Even though my computer projects all three to finish undefeated, with Oklahoma State still having to play Kansas State, Texas Tech, and OU and Stanford hosting Oregon and going to ASU, the two losses could reasonably happen.
So, is Boise State "in" in that case? One can make that case, there'd be only two undefeated teams (ok, Houston too) so they should be in right? That might be the "right" result, but right and wrong doesn't always happen with the BCS. We have to look at how the BCS, polls, and computers work to get a better idea.
First, it isn't safe to assume that Boise State simply not losing will preserve their position in the BCS. We already saw Stanford pass them this week, going from 0.02 back to 0.01 ahead, even though it took them three OTs. This is because the BCS computers, not being able to factor MOV in, can move a team up with a narrow win over a good team or can move a team down even in a win, if the opponent is weak.
Stanford is a perfect example of this as their early schedule wasn't that strong (66.7 by my computer before playing USC) and the computers had them averaging a #9 ranking behind one loss Oklahoma and Arkansas last week before playing USC. BSU's schedule on the other hand is front loaded, strong enough to date (71.7, on par with Alabama's 71.0, better than Stanford's) but they finish with TCU and four weak teams meaning their schedule could end up around 68.5. It is having to play these weak teams that could hurt them in the computers. See Houston with a weak schedule (61.9) being undefeated but an average of 13 in the computers, and not even top-25 in one of them. BSU's schedule won't get this low, but you get the idea, they could give up a spot or two in the computers.
So what one-loss team might move ahead in the computers? Oklahoma is already ahead in one computer and no more than 2 spots behind in any other, and if they win out beating Oklahoma State I'd expect they'd be ahead in most if not all of them. Then the LSU/Alabama loser, particularly if it is Alabama given they'll get to recover playing tough opponents South Carolina and Auburn plus decent opponent Mississippi State, could very well move ahead. And if Stanford loses it is likely to Oregon so they'd have a chance, but they are a ways back in the computers.
Second, there are pollsters like Craig James that simply refuse to rank BSU high because of their "body of work", and their finishing schedule is not going to convince them otherwise. It is entirely likely that a one-loss LSU, Alabama, or Oklahoma could at least be close to BSU in the human polls if not ahead because of this. And if they are even just close, the computers giving the nod to one of them over BSU could move them ahead in the BCS.
For example, BSU is 4th in the computers this week with a 0.870 percentage ahead of OU at #5 and 0.820. If Oklahoma State and Stanford lose, BSU and OU would move up naturally to #2 and #3, but for the reasons listed above I'd guess OU moves ahead to #2 in most computers leaving OU with a likely 0.960 percentage to BSU at 0.920. And a one-loss Alabama/LSU could also shake things up so the gap could perhaps be more than 0.04, say at least 0.05.
Given that, BSU would need to make that up in the polls. Today's polls have OU two spots back, 280 and 120 points and 0.09 and 0.08 percentage respectively, but they have more room to move up and fill the Stanford/Oklahoma State void, and beating Oklahoma State would impress the voters meaning I expect them to be no more than 80 and 40 points back at the worst, or about a 0.02 to 0.03 percentage. That small gap plus the advantage in the computers puts them in a dead heat for the #2 BCS spot when you do the math.
It would ultimately come down to the poll voters deciding if they are going to vote honestly or if they are going to begin to manipulate the system based on whether they think BSU should be given a chance or not. You can easily see some voters keeping them behind not just OU but a one-loss LSU/Alabama and perhaps even Oregon as they are ahead of OU today and in this scenario they would have beat Stanford. Some voters could decide to vote them #1 to manipulate things that way, but that is harder to do and less ability to impact as you can only go so high but you can drop them a ways.
In any case, this exact scenario will probably not happen, but it is still interesting to think what will happen if it does.