I did not follow college football this year like I should have, mainly because my team had a very disappointing season. I checked the college football rankings yesterday and was surprised to see that there were five undefeated teams this year. Two of these teams (Alabama and Texas) will get to play for the national championship and the other three (Cincinnati, TCU, and Boise State) basically get a consolation prize.
The reason for this is that the Bowl Championship Series (BCS) was designed for picking out the best two teams. It uses a complex algorithm based in part on national rankings, difficulty of schedule, and win-loss records. It is tweaked periodically. Almost everyone likes to beat up on the BCS system. The BCS algorithm seems to work fine. It ends up with rankings almost identical to the consensus of experts (with a few notable exceptions). The problem is more in how it is used. It is used to pick the top two teams, assuming that the rest should not have a chance at the national championship. This year, it seems like at least three other teams deserve a shot at the national championship.
The announcement of the bowl games were announced last night signaled the start of the complaining-about-the-BCS system. The most common proposal for reforming the BCS is starting an eight team playoff (even our President endorses this idea). Can OR play a role in reforming the BCS?
Wayne Winston’s Huffington Post article analyzes the BCS issue from an OR point of view. He weighs the pros and cons of the current BCS system (debunking the pros along the way). The best part is when he describes what an eight-team playoff would look like. This is important, since we all know what the problem is, but we need to know what the new system would look like if we were to endorse it.
Using power ratings for each year we took the two BCS selected teams and the next 6 ranked teams and used the Palisade Excel Monte Carlo simulation add-in @RISK to play out an 8 team tournament 5000 times. We seeded the BCS selected teams 1 and 2 in the tournament, so they received the easiest possible road to the title game. We found that one of the BCS’ top two teams won only 50% of the time. Even in 2005 when nobody doubted that USC and Texas should have played for the title, there was a 23% chance that both these teams would have been knocked off in an 8 team tournament. So how can the BCS claim they are crowning a legitimate champion?
Link: Read Wayne Winston’s article.