Passer rating
Passer rating is the name of the method for evaluating the performance of quarterbacks and any other passers in American football. There are at least two formulas currently in use: one officially used by the National Football League and the Canadian Football League, and one used in college football.
The Passer Rating is calculated using each quarterback's completion percentage, passing yardage, touchdowns and interceptions . The NFL's current "passer rating" or "quarterback rating" system (the former term being the official one) was conceived by Pro Football Hall of Fame's Don Smith in 1973; it was then applied retroactively to all previous seasons. The system is of a sliding-scale design, where outstanding performances meet diminishing returns faster than sub-par ones. The best passer rating that a quarterback can obtain under it is 158.3 (technically 158.333→), while the worst is zero. Conceptually, the average rating would be 79.2 (technically 79.166→), since this is equidistant between zero and 158.3, but the architects of the rating had 66.66→ in mind as the "average" score (100 * [1.00*4]/6). The cumulative league-wide average passer rating for the years 2000 through 2003, all inclusive, was 78.9 (the figure is typically rounded to the nearest 1/10 of a point); however in 2004 the league average was 82.8, the highest ever recorded. This may be due, at least in part, to stricter rules regarding pass interference.
The passer rating is known formally in college football as the passing efficiency rating; it is based on player performances between 1965 and 1979.
Calculation
NFL and CFL
The passer rating is determined by four statistics, each of which are computed as a number between zero and 2.375. The benchmarks for these statistics are based on historical averages. If any of the components are less than zero, they are reckoned as zero; if any are over 2.375, they are reckoned as 2.375.
- The completion percentage rating is calculated as ((COMP/ATT) * 100) - (30/20)
- The rating for average yards per attempt is calculated as ((YDS/ATT) - 3) * (1/4)
- The rating for touchdowns per attempt is calculated as (TD/ATT) * 20
- The rating for interceptions per attempt is calculated as 2.375 - (INT/ATT) * 25
The four results are then added, divided by 6, and multiplied by 100. Since each of these numbers is at most 2.375, the maximum passer rating is
((4 * 2.375) / 6) * 100 = 158.3.
The CFL appears to use the same formula as the NFL.
College Football
As in the NFL, the pass efficiency rating is based on five quarterback statistics: passing yards, touchdowns, interceptions, completions, and attempted completions. However, the formula is significantly different and there is no cap on the passer rating in college; accordingly, NFL and NCAA passer ratings are not comparable. Indeed, while 100 would be a relatively good passer rating in the NFL, almost every starting quarterback in NCAA Division I-A has a pass efficiency rating above 100.
The formula used in college football is:
((8.4 * YDS) + (330 * TD) - (200 * INT) + (100 * COMP))/ATT [1]
Criticisms
The Passer Rating System has many critics, who have objected to it on several different grounds.
The most frequently-voiced objection is that plays on which the quarterback is sacked do not count toward compiling the rating, thereby giving a quarterback, who is about to be sacked, an incentive to deliberately take the sack rather than throw the ball away and have an incomplete pass lower his completion percentage, touchdown passes-per-attempt ratio and his yards-per-attempt ratio.
Another criticism is the fact that rushing yards gained by a quarterback do not result in his getting a higher rating — a particularly important contemporary issue due to the recent emergence of many excellent running quarterbacks in the NFL, most notably Steve Young, Daunte Culpepper, Donovan McNabb, John Elway and Michael Vick. On the other hand, Vick holds the NCAA freshman record for passing efficiency and Young is the former record holder for passer rating in a season. This record was shattered in 2004 by Indianapolis Colts quarterback Peyton Manning.
Some observers have proposed replacing yards per attempt with yards per play as one of the rating's components, counting both sacks and rushing attempts (in addition to passes actually thrown) as plays, thereby resolving both of the above issues.
A third complaint concerns the placing of artificial limits (both upper and lower) on the points that can be earned in the various categories. Critics claim, for example, that it is unfair not to give a quarterback a higher rating for completing 90% of his passes than for completing 77.5%, or for averaging, say, 15 yards per attempt as opposed to only 12.5 (the limit of 2.375 applying in each instance) — although this is likely to affect only the rating for a single game and not for an entire season. As well as encountering problems when approaching the arbitrary limits for performance, the system is biased inasmuch as some of the "benchmarks" are more achievable than others: A 2.00-worthy performance in Completion % is far easier to obtain than a 2.00 in the Touchdown % category. In fact, until recent years, the league norms in each non-Completion % category were below the formula's expected "average" figures.
Yet another criticism is that the formula overemphasizes Completion Percentage. While Completion % in and of itself makes up 25% of the rating's calculation, the use of Yards per Attempt rather than Yards per Completion adds to the weight of Completion %, since incomplete passes are penalized under yds/attempt. Thus, many critics feel that the Passer Rating formula automatically is skewed in favor of quarterbacks (like Steve Young, who held the single-season record until 2004) who play in a West Coast scheme that favors many high-percentage (but low-yardage) pass plays.
The most simple complaint may be that the weighting of each category is, on the whole, arbitrary. There is not a shred of evidence to suggest that Completion %, Yards/Attempt, Touchdown %, and Interception % are of equal value (25% each) in terms of an offense's efficiency (or if those stats, in that combination, have any correlation to scoring at all). The system also does not account for changing offensive conditions in the NFL over time; for example, when the formula was devised, a score of 66.6 was supposed to represent an average quarterback. And in 1970, the average passer scored a 65.6, a figure almost perfectly in line with the rating-creators' vision. But in 1980, the average was 73.7; in 1992, the average quarterback had a rating of 75.3; and in 2004, a record-setting year for passers, the league's mean passer rating was 82.8. Thus, scores have no significance when doing cross-era analysis.
Leaders
Steve Young currently holds the NFL record for the highest career passer rating with a mark of 96.8. He previously held the all-time record for highest single season rating in the league when he scored a 112.4 in 1994. That record, along with virtually every other significant seasonal quarterbacking record, was shattered in 2004 by Peyton Manning, who posted a rating of over 121.1. Also in 2004, rookie Ben Roethlisberger posted a mark of 98.1, setting a new record for first-year passers.
In 2005, Manning retained the highest passer rating in the AFC at 104.3, while Matt Hasselbeck led all passers in the NFC at 98.1.
In NCAA Division I-A, the career record for passing efficiency is held by Ryan Dinwiddie of Boise State, who had a career mark of 168.9 between 2000 and 2003. The single-season record belongs to Shaun King of Tulane, who amassed a passer rating of 183.3 over the 1998 season, while the freshman record belongs to Michael Vick of Virginia Tech, whose rating during the 1999 season was 180.4.[2]. Current NCAA Division I-A passing efficiency ratings can be found here.
External links and references
- NFL.com QB Rating Page
- Online passer rating calculator for NFL/CFL, NCAA and AFL formulas
- QB Rating Story/ GQ Magazine Article Explaining how it works and why
- All-Time Top NFL Passer Ratings List
- New York Times - The N.F.L.'s Passer Rating, Arcane and Misunderstood - January 14, 2004
