Total quarterback rating
Encyclopedia
Total Quarterback Rating (abbreviated as Total QBR or simply QBR) is a measure of the performance of quarterback
s or any other passers in American football
developed by the American sports network ESPN
in 2011. The network claims it is a more meaningful alternative to the older NFL passer rating, which remains the official NFL measure of quarterback performance.
for the team, and also to a win by the team. For example, completing a pass
to earn a first down at the quarterback's own 20-yard-line with 30 seconds left in the game is unlikely to lead to any points for his team, but if they are already leading it increases the probability
of winning, as it usually enables the leading team to run out the clock. This second criterion is quantified using a "win probability" function
which ESPN developed by analyzing data for each play of NFL games over the previous decade.
The computation requires an examination of each play in which the quarterback was involved. For each play, the change in the expected value
of the points scored by the two teams is determined along with the maximum possible change in points for each team. The net points gained by the offense on the play are divided between the players involved in the play based on how much each contributed to the points gained or lost. For example, on a play where the quarterback immediately hands the ball off to a running back
after the snap, the quarterback's contribution is negligible. On passing plays the quarterback is likely to have a major contribution, along with the blockers
and the receiver
. The resulting value is compared the maximum possible net point gain, and this comparison leads to a "net points percentage" value between 0 and 100 for the quarterback on each play which roughly represents the percentage of the possible point gain that the quarterback produced. This value is transformed so that a value of 50 represents the average net point gain of an NFL quarterback on the play.
The win probability function is then used to compute a "clutch
index" for each play ranging from 0.3 to 3.0, with higher values corresponding to plays that have a greater influence on winning or losing the game. The QBR is obtained by taking the weighted average of the "points gained percentage" for each play, with each play having a weight equal to its clutch index. Thus the QBR has a range from 0 to 100 with 50 being considered average.
s and interceptions, and has a maximum value of 158.3 and minimum value 0, with 80 being considered average.
. In an interview with San Diego's XX Sports Radio, San Diego Chargers
quarterback Philip Rivers
seemed baffled by the ratings, which put him ninth overall in its metrics for the 2010 season, saying "I still don't get it. I think it's more complicated now".
In an op-ed piece published by Deadspin
, they opine that the clutch index component of the QBR "looks like a weirdly applied version of baseball's leverage metric and which, tellingly, is the sort of mindless branding you get when the network of 'Who's Now' starts dicking around with numbers.". And the Baltimore Sun's Matt Vensel wrote, "I can’t say the new rating system ... is any better. And that's because I don’t really understand or care to understand how Total Quarterback Rating works".
Michael David Smith
of Profootballtalk.com
explained the major drawback of QBR:
On the other side, noted football author and researcher Brian Burke of Advanced NFL Stats
opined that QBR was superior to the traditional passer rating. The main advantages, in his opinion, are QBR's accounting for many more events in quarterback play than the old rating, and the fact that it avoids the double-counting
that plagues the official NFL passer rating. He did however lament the proprietary nature of the statistic, and predicted it would not become widely used so long as its precise computation details were kept secret (e.g. it is unlikely that CBS
, Fox
, NBC
, and other competing media outlets would want to heavily promote something that is proprietary to ESPN).
Further controversy erupted when the Total QBR system gave the Denver Broncos
' Tim Tebow
a higher rating than the Green Bay Packers
' Aaron Rodgers
in their respective Week 5 contests. Noting that Rodgers completed 26 of 39 passes for 396 yards and two touchdowns in a win over the Atlanta Falcons
, while Tebow completed four of 10 passes for 79 yards and a touchdown, and six rushes for 38 yards and a touchdown, in a loss to the San Diego Chargers
, Mike Florio of Profootballtalk.com wrote that he'll "continue to ignore ESPN’s Total QBR stat." Rodgers himself was surprised: "I saw the [QBR stats] and chuckled to myself. I played a full game, [Tebow] played the half. He completed four passes, I completed 26. I think it incorporates QB runs as well ... The weighting of it doesn't make a whole lot of sense." ESPN's Stats and Information Group explained that Tebow's higher rating was the result of him staging a partial comeback, taking no sacks, and having positive rushing yards and a rushing touchdown, among other factors. However, Doug Farrar of Yahoo! Sports
wrote that the QBR system lacks a minimum performance frequency floor that players must meet before they can be rated, and thus it essentially penalizes Rodgers because he played throughout the entire game, while awarding Tebow because he came off the bench in the second half in an attempt to stage a comeback.
Quarterback
Quarterback is a position in American and Canadian football. Quarterbacks are members of the offensive team and line up directly behind the offensive line...
s or any other passers in American football
American football
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...
developed by the American sports network ESPN
ESPN
Entertainment and Sports Programming Network, commonly known as ESPN, is an American global cable television network focusing on sports-related programming including live and pre-taped event telecasts, sports talk shows, and other original programming....
in 2011. The network claims it is a more meaningful alternative to the older NFL passer rating, which remains the official NFL measure of quarterback performance.
Summary of computation
According to ESPN, QBR was developed to measure the degree to which a quarterback contributed to scoring pointsScore (game)
In games, score refers to an abstract quantity associated with a player or team. Score is usually measured in the abstract unit of points, and events in the game can raise or lower the score of different parties...
for the team, and also to a win by the team. For example, completing a pass
Forward pass
In several forms of football a forward pass is when the ball is thrown in the direction that the offensive team is trying to move, towards the defensive team's goal line...
to earn a first down at the quarterback's own 20-yard-line with 30 seconds left in the game is unlikely to lead to any points for his team, but if they are already leading it increases the probability
Probability
Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...
of winning, as it usually enables the leading team to run out the clock. This second criterion is quantified using a "win probability" function
Function (mathematics)
In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
which ESPN developed by analyzing data for each play of NFL games over the previous decade.
The computation requires an examination of each play in which the quarterback was involved. For each play, the change in the expected value
Expected value
In probability theory, the expected value of a random variable is the weighted average of all possible values that this random variable can take on...
of the points scored by the two teams is determined along with the maximum possible change in points for each team. The net points gained by the offense on the play are divided between the players involved in the play based on how much each contributed to the points gained or lost. For example, on a play where the quarterback immediately hands the ball off to a running back
Running back
A running back is a gridiron football position, who is typically lined up in the offensive backfield. The primary roles of a running back are to receive handoffs from the quarterback for a rushing play, to catch passes from out of the backfield, and to block.There are usually one or two running...
after the snap, the quarterback's contribution is negligible. On passing plays the quarterback is likely to have a major contribution, along with the blockers
Blocking (American football)
In American football, blocking is a legal move occurring when one player obstructs another player's path with his body. The purpose of blocking is to prevent defensive players tackling the ball carrier, or to protect the quarterback while attempting to pass or hand-off the ball...
and the receiver
Reception (American football)
In American football, a reception is part of a play in which a forward pass from behind the line of scrimmage is received by a player in bounds, who, after the catch, proceeds to either score a touchdown or be downed. Yards gained from the receiving play are credited to the player as receiving...
. The resulting value is compared the maximum possible net point gain, and this comparison leads to a "net points percentage" value between 0 and 100 for the quarterback on each play which roughly represents the percentage of the possible point gain that the quarterback produced. This value is transformed so that a value of 50 represents the average net point gain of an NFL quarterback on the play.
The win probability function is then used to compute a "clutch
Clutch (sports)
In American sports terminology, "clutch" means performing well under extreme pressure. It often refers to high levels of production in a critical game, such as Game 7 of a best-of-seven series, the last hole of a Major Championship golf tournament, or the final minute in a close match...
index" for each play ranging from 0.3 to 3.0, with higher values corresponding to plays that have a greater influence on winning or losing the game. The QBR is obtained by taking the weighted average of the "points gained percentage" for each play, with each play having a weight equal to its clutch index. Thus the QBR has a range from 0 to 100 with 50 being considered average.
Comparison to NFL Passer Rating
The calculation of the NFL passer rating is much simpler than the QBR, as it depends only on aggregate statistics rather than an analysis of each play a quarterback is involved in. Passer rating is calculated using each quarterback's completion percentage, passing yardage, touchdownTouchdown
A touchdown is a means of scoring in American and Canadian football. Whether running, passing, returning a kickoff or punt, or recovering a turnover, a team scores a touchdown by advancing the ball into the opponent's end zone.-Description:...
s and interceptions, and has a maximum value of 158.3 and minimum value 0, with 80 being considered average.
Reception
Unlike the NFL passer rating, ESPN has not yet been forthcoming on the exact specific formulas and procedures to calculate QBR. The proprietary, complex methodology spans some 10,000 lines of codeLine (text file)
In computing, a line is a unit of organization for text files. A line consists of a sequence of zero or more characters, usually displayed within a single horizontal sequence....
. In an interview with San Diego's XX Sports Radio, San Diego Chargers
San Diego Chargers
The San Diego Chargers are a professional American football team based in San Diego, California. they were members of the Western Division of the American Football Conference in the National Football League...
quarterback Philip Rivers
Philip Rivers
Philip Rivers is an American football quarterback for the San Diego Chargers of the National Football League . He was one half of the Manning-Rivers draft trade which sent him to San Diego and the 1st overall pick, Ole Miss quarterback Eli Manning, to the New York Giants. Rivers played college...
seemed baffled by the ratings, which put him ninth overall in its metrics for the 2010 season, saying "I still don't get it. I think it's more complicated now".
In an op-ed piece published by Deadspin
Deadspin
Deadspin is a sports website owned by Gawker Media and was launched in September 2005. As of February 2010, the site had attracted over 462 million unique visitors and about 573 million page views....
, they opine that the clutch index component of the QBR "looks like a weirdly applied version of baseball's leverage metric and which, tellingly, is the sort of mindless branding you get when the network of 'Who's Now' starts dicking around with numbers.". And the Baltimore Sun's Matt Vensel wrote, "I can’t say the new rating system ... is any better. And that's because I don’t really understand or care to understand how Total Quarterback Rating works".
Michael David Smith
Michael David Smith
Michael David Smith is a writer based in Chicago. In 2007 he was named Mainstream Media Sports Blogger of the Year by Sports Illustrated.Smith is best known for his work at the AOL FanHouse on MMA. He has also written for The New York Times, The New York Sun, ESPN the Magazine, Fox Sports, Football...
of Profootballtalk.com
Profootballtalk.com
Profootballtalk.com is a news and rumor website that focuses on the National Football League. Though much of the information on PFT is aggregated from mainstream media sources, site editor Mike Florio often writes stories based on tips he attributes to a network of sources.The main focus of the...
explained the major drawback of QBR:
On the other side, noted football author and researcher Brian Burke of Advanced NFL Stats
Advanced NFL Stats
Advanced NFL Stats is a website dedicated to the analysis of the National Football League using advanced mathematical and statistical methods. The site's lead author is noted football researcher and analyst Brian Burke...
opined that QBR was superior to the traditional passer rating. The main advantages, in his opinion, are QBR's accounting for many more events in quarterback play than the old rating, and the fact that it avoids the double-counting
Double counting (fallacy)
Double counting is a fallacy in which, when counting events or occurrences in probability or in other areas, a solution counts events two or more times, resulting in an erroneous number of events or occurrences which is higher than the true result...
that plagues the official NFL passer rating. He did however lament the proprietary nature of the statistic, and predicted it would not become widely used so long as its precise computation details were kept secret (e.g. it is unlikely that CBS
NFL on CBS
The NFL on CBS is the brand name of the CBS television network's coverage of the National Football League's American Football Conference games, produced by CBS Sports.-Market coverage and television policies:...
, Fox
NFL on FOX
NFL on Fox is the brand name of the Fox Broadcasting Company's coverage of the National Football League's National Football Conference games, produced by Fox Sports...
, NBC
NFL on NBC
NFL on NBC is the brand given to NBC Sports coverage of National Football League games until 1998, when NBC lost the NFL American Football Conference rights to CBS...
, and other competing media outlets would want to heavily promote something that is proprietary to ESPN).
Further controversy erupted when the Total QBR system gave the Denver Broncos
Denver Broncos
The Denver Broncos are a professional American football team based in Denver, Colorado. They are currently members of the West Division of the American Football Conference in the National Football League...
' Tim Tebow
Tim Tebow
Timothy Richard "Tim" Tebow is an American football player who is currently the starting quarterback for the Denver Broncos of the National Football League . He was drafted by the Broncos as the 25th overall pick in the 2010 NFL Draft...
a higher rating than the Green Bay Packers
Green Bay Packers
The Green Bay Packers are an American football team based in Green Bay, Wisconsin. They are members of the North Division of the National Football Conference in the National Football League . The Packers are the current NFL champions...
' Aaron Rodgers
Aaron Rodgers
Aaron Charles Rodgers is an American football quarterback for the Green Bay Packers of the National Football League . Rodgers was selected in the first round of the 2005 NFL Draft by the Packers...
in their respective Week 5 contests. Noting that Rodgers completed 26 of 39 passes for 396 yards and two touchdowns in a win over the Atlanta Falcons
Atlanta Falcons
The Atlanta Falcons are a professional American football team based in Atlanta, Georgia. They are a member of the South Division of the National Football Conference in the National Football League...
, while Tebow completed four of 10 passes for 79 yards and a touchdown, and six rushes for 38 yards and a touchdown, in a loss to the San Diego Chargers
San Diego Chargers
The San Diego Chargers are a professional American football team based in San Diego, California. they were members of the Western Division of the American Football Conference in the National Football League...
, Mike Florio of Profootballtalk.com wrote that he'll "continue to ignore ESPN’s Total QBR stat." Rodgers himself was surprised: "I saw the [QBR stats] and chuckled to myself. I played a full game, [Tebow] played the half. He completed four passes, I completed 26. I think it incorporates QB runs as well ... The weighting of it doesn't make a whole lot of sense." ESPN's Stats and Information Group explained that Tebow's higher rating was the result of him staging a partial comeback, taking no sacks, and having positive rushing yards and a rushing touchdown, among other factors. However, Doug Farrar of Yahoo! Sports
Yahoo! Sports
Yahoo! Sports was launched on December 8, 1997. It receives a majority of its information from STATS, Inc., employs various writers, and has team pages for teams in almost every North American sport...
wrote that the QBR system lacks a minimum performance frequency floor that players must meet before they can be rated, and thus it essentially penalizes Rodgers because he played throughout the entire game, while awarding Tebow because he came off the bench in the second half in an attempt to stage a comeback.