Friend of ANS Aaron Gordon used the Excitement Index (EI) and Combeback Factor (CBF) to find out if the Thursday night games really are more boring than most games. From Aaron's article at Sports on Earth:
What NFL Network games have sorely missed are big comebacks. NFL Network games average a Comeback Factor 3.32 -- half the league average -- and only five games with a CBF of 5 or above (where the winning team had a win probability below 20 percent). By definition of the win probability model, 20 percent of the games played should feature a comeback with a CBF of 5 or above (which the larger data set confirms). For NFL Network games, its only 13 percent. For comparison, Monday night games --which often feature hand-picked matchups -- have an average CBF of 8.15, but are right about where they should be in terms of CBF games of 5 or above: 23 percent.
I have always wondered is this because of the poor matchups, or does the short rest leading up to the game have an affect on teams.
There is something I don't get here. How is a CBF of <2 possible? It seems to me that the lowest possible number for a CBF is 2 by definition. The losing team has a 50% probability of winning the game as of the opening kickoff. (I know this isn't actually true but the winprob numbers at ANS do not weight for pregame lines). Anyway, in a situation where one team dominates from the opening kickoff, the losing teams maximum WP was 50% so the comeback factor would have to be 2 (1/0.5).
You say that there were 4 games with a CBF of 1. That would seem to be impossible unless the winning team's lowest possible point was at a 100%. What am I missing here?
I also disagree with :
"By definition of the win probability model, 20 percent of the games played should feature a comeback with a CBF of 5 or above"
That strikes me as if it is confusing a couple of issues. Remember the probability is based on the win probability at that specific point. The CBF is based on the low point. The percentage of games where the winner at one point touched a number below 20% should be well higher than 20%. Its the same reason why the average stock is up considerably over its 52 week high even if its only performing like an average stock.
Likewise, the following quote is off:
"In 13 years of games, there have been 64 CBFs of 100; or, to put another way, there have been 64 instances where the eventual victor only had a 1 percent chance of winning some point in the game, but came back. (Not-coincidentally, 64 games is just about 1 percent of all games played since 2000. Magic, right?)"
First off, there's been around 3400 games, so 64 is closer to 2%. Furthermore, They should be winning 1% of the games in which the WP drops to 0.01. Technically, yes, I know all games get there at some point. But 0.01 at halftime is different than than the 0.01 that happens when the winning team has the ball with one snap to play.
Is the WP model a little off at the extremes, or is this person just grabbing your stats and talking out of a well used orifice?
Joe, there have been 3400 games, each involving two teams, either of which could have been down to 1% WP.