A few years back, I tried to answer the question of how much bye weeks matter. It was in the 2010 offseason as we were heading towards a year in which Alabama played a lot of teams off of their bye weeks. The conclusion I came up with was that byes don't actually do a whole lot; they were maybe slightly helpful to underdogs and possibly unhelpful if anything for anyone else.
Unfortunately, the criteria I used for categorizing games wasn't good at all. It was based on number of wins, and every passing year teaches me just how unreliable a stat that wins are for judging quality of teams. If you disagree, I would refer you to every argument about Boise State ever.
Anyhow, I overhauled the system to use F/+ instead of wins. This makes it more robust, but because ratings under the current F/+ formula only go back to 2007, I only have six seasons' of data to work with here. That's your disclaimer for everything here: a small sample size could be messing with the results.
If the end-of-year F/+ ratings for teams were within ten percentage points of each other, I called the game a tossup. If the difference was greater than ten percentage points, then it was a mismatch. Why ten percentage points? It just seemed right as I looked over the SEC's games of the past six seasons. That part is necessarily subjective, and that's where I drew the line.
The stats on games after bye weeks only apply to SEC vs. SEC games. I tossed out any games in which both teams had a bye going in, because both teams would have gotten any benefit from the week off.
There are three categories of games here, so let's dive in.
The team coming off of the bye was favored
There were 17 SEC games in the past six seasons that were mismatches with the better team coming off of a bye. The favorites were 16-1 in those games, with the one loss being a bad Arkansas team (F/+ of -4.6%) falling to an even worse Mississippi State team (-16%).
That record gave favorites a winning percentage of .941. By comparison in all SEC mismatches over the same span, favorites had a winning percentage of .897. It might appear that the bye helps out favorites, but keep in mind the small sample size. Just one more favorite falling would have given them a winning percentage of .882, which is right there with the overall percentage.
I'm going to call this one even. Bye weeks might help favorites to a small degree, but it's too tough to say right now.
The team coming off of the bye was not favored
There were 20 SEC games in the past six seasons that were mismatches with the weaker team coming off of a bye. Those weaker teams were just 2-18, with the upsets being that same 2008 Mississippi State team (-16%) beating Vanderbilt (1.8%) and 2010 South Carolina (21.9%) taking out Alabama (37.5%) in Stephen Garcia's finest game.
The winning percentage works out to a nice and tidy .100 for these teams. For underdogs in overall SEC play, the winning percentage was .103. It's right on. In aggregate, underdogs didn't receive any benefits from having a week off.
In these games, the teams were close but only one had a bye. There were 17 such games in the past six years. The team coming off of the bye had an overall winning percentage of .647. Given that these are supposed to be tossups, the winning percentage should have been close to .500 if byes had no effect. Instead, it was well above .500.
Again, the sample size is small, but it does appear that having a bye will help in tossup games. It would take two or three games going the other way to get that winning percentage close to .500 rather than just the one game being different for favorites.
Bye weeks don't appear to matter much in mismatches. The favored team will probably win those no matter who is or is not coming off of a bye. They might, however, be noticeably helpful in tossup games.
So let's apply it to this season. What are the post-bye games looking like for the fall? For this, I'm using the projected F/+.
|Team||F/+||Post Bye Opp.||F/+||Type||Venue|
|Ole Miss||9.8%||Alabama||37.8%||Not Favored||Road|
|Miss St.||1.9%||LSU||22.9%||Not Favored||Home|
|Tennessee||3.9%||South Carolina||17.3%||Not Favored||Home|
|Texas A&M||19.4%||Ole Miss||9.8%||Tossup||Road|
The biggest potential beneficiary of bye weeks is Arkansas. It has both of its bye weeks before tossup games, and both of those games are at home. Also, keep in mind with Alabama that its projected F/+ is so high, it would be an upset by my ten percentage points rule for the Tide to lose to anyone except Oregon.