Passer rating

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Passer rating is a measure of the performance of quarterbacks or any other passers in American football. There are at least two formulae 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 passing efficiency or pass efficiency; it is based on player performances between 1965 and 1979.

1 Calculation
- 1.1 NFL and CFL
- 1.2 Perfect rating
2 Criticisms
3 Leaders
4 External links and references

[edit] Calculation

[edit] 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 <math>{{COMP \over ATT} \times 100 - 30 \over 20}</math>

The rating for average yards per attempt is calculated as <math>\left( { YDS \over ATT } - 3 \right) \times { 1 \over 4 }</math>

The rating for touchdowns per attempt is calculated as <math>{ TD \over ATT }\times 20</math>

The rating for interceptions per attempt is calculated as <math>2.375 - { INT \over ATT } \times 25</math>

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

<math>{4 \times 2.375 \over 6}\times 100 = 158.3</math>.

[edit] Perfect rating

A perfect completion percentage is 77.5%: <math>2.375 \times 20 + 30 = 77.5</math>

A perfect average yards per attempt is 12.5 or better: <math>2.375 \times 4 + 3 = 12.5</math>

A perfect touchdowns per attempt is .11875, or 8.42 attempts per touchdown: <math>{2.375 \over 20} = .11875</math>

A perfect number of interceptions is zero: <math>{ATT \times (2.375 - 2.375) \over 25} = 0</math>

The CFL appears to use the same formula as the NFL.

[edit] 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. However, many defenders have pointed out that no professional quarterback would intentionally take a sack to the detriment of his team in order to preserve a passer rating.

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, Donovan McNabb, John Elway and Michael Vick and players like Damon Allen and Kerry Joseph in the CFL. On the other hand, Vick holds the NCAA freshman record for passing efficiency and Young is the former NFL 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, 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 who play in a West Coast scheme that favors many high-percentage (but low-yardage) pass plays, e.g. Steve Young, who held the single-season record until 2004.

The simplest complaint may be that the weighting of each category is, on the whole, arbitrary. There is no 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 must be interpreted with care when doing cross-era analysis.

[edit] Leaders

Steve Young currently holds the NFL record for the highest career passer rating with a mark of 96.8. The highest passer rating for a complete season is 121.1 set by Peyton Manning in 2004. Also in 2004, rookie Ben Roethlisberger posted a mark of 98.1, setting a new record for first-year passers.

For 2006 to date (November 26), Tony Romo has the highest passer rating in the NFC, at 102, while Peyton Manning again leads the AFC at 100.2.

In CFL football Dave Dickenson of the BC Lions has produced some of the highest professional passing efficiency numbers. Although limited by injuries in 2005, he set two regular season records with a 74 percent completion percentage and an efficiency rating of 118.8. His numbers for the year were: 253/342, 3338 yards, 74% completion rate, 21 TDs, 5 INTs. He opened the 2006 CFL season by setting a CFL single-game passing efficiency rating record of 150.61. He capped 3 of the 4 criteria for passing efficiency and was 28/34, 362 yards, 5 TDs, 0 INTs.

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.[1]. Current NCAA Division I-A passing efficiency ratings can be found here.