Also called the pass efficiency rating, a statistical measure of the overall ability of a quarterback. As with most statistics, it lies... awarding a higher rating to quarterbacks who throw short passes*
(see: West Coast Offense
), completely ignoring a quarterback's escapability
and running ability, and punishing quarterbacks in offensive schemes where rushing is prevalent‡
The following equation, adopted in 1973, is used to calculate quarterback rating in the NFL (college football uses a different scheme):
(CP + YG + TP + IP) * 16.67
CP = (completion percentage - 30) * .05
if CP < 0, CP = 0
if CP > 2.375, CP = 2.375
YG = (average yards gained per attempt - 3) * .25
if YG < 0, YG = 0
if YG > 2.375, YG = 2.375
TP = touchdown percentage * .2
if TP > 2.375, TP = 2.375
IP = 2.375 - (interception percentage * .25)
if IP < 0, IP = 0
Using that equation, you can see that the highest possible quarterback rating is 158.3. Steve Young
holds the record for the highest actual QB rating in a season, with 112.8 in 1994 (461 attempts, 324 completions, 3,969 yards, 35 touchdowns, 10 interceptions).
* While YG compensates for short passes, short passing schemes result in a much higher completion percentage, and yards after catch (YAC) are all credited to the quarterback as well. So, if a QB throws a pass to a receiver one yard downfield, who then jolts down the field for forty more yards, the quarterback is rewarded with a 41 yard pass.
‡ While a team that focuses on the running game will tend to have a quarterback with fewer attempts, they are also more likely to run on every down inside the red zone, forcing a quarterback to earn his touchdowns on long, low percentage passes.