How much is Tebow overperforming?
An examination of how QBR relates to expected team wins and losses
When Total QBR was introduced before the season, the interpretation provided was that on a game level, Total QBR is a 0-100 number that represents the percentile ranking of how good the quarterback's game was compared to all other QB games from 2008 to 2010. So if a QB finishes with a Total QBR of 80 in a game, his performance in that game ranked better than roughly 80 percent of all QB games in that time.
To read why Tim Tebow and Aaron Roders are overperforming, as well as which QBs should have more wins this year, you must be an ESPN Insider.