Total QBR is a quarterback rating that takes into account all of a quarterback's contributions (passing, rushing, sacks, fumbles, penalties) to his team's scoring and winning and summarizes them into one number on a 0-100 scale, on which 50 is average.
For a season, a Total QBR of 65 or better is roughly Pro Bowl level, and a rating of 75-plus is MVP level. For more about the methodology and statistics behind Total QBR, see here.
Aaron Rodgers continues to lead the league in QBR, although his lead over Drew Brees and Tom Brady did shrink slightly after an off performance against the Lions was coupled with 90-plus games from Brady and Brees.
The two worst performers of Week 12 also happen to be the two worst performers of the season. Blaine Gabbert and Curtis Painter continue to be the bottom two qualified quarterbacks in QBR, with a Week 17 matchup looming that might decide who the worst QB of the season will be.
Below is the full breakdown of Total QBR and its component statistics for the 35 NFL QBs on pace for 250 action plays this season.