Total quarterback rating

Last updated

Total quarterback rating (abbreviated as total QBR or simply QBR) is a proprietary statistic created by ESPN in 2011 to measure the performance of quarterbacks in American football. According to ESPN, "QBR incorporates all of a quarterback's contributions to winning, including how he impacts the game on passes, rushes, turnovers, and penalties. Since QBR is built from the play level, it accounts for a team's level of success or failure on every play to provide the proper context, then allocates credit to the quarterback and his teammates to produce a clearer measure of quarterback efficiency." [1]

Contents

ESPN claims that it created QBR to be a more meaningful alternative to the traditional passer rating statistic. [1] However, ESPN has never released the complete formulas and procedures to calculate QBR, [2] resulting in criticism among fans and commentators alike questioning the results. [3]

History and development

Total QBR was developed by a team at ESPN Stats & Information Group including Jeff Bennett, Dean Oliver, Alok Pattani, Albert Larcada, and Menlo College professor Ben Alamar. The group also received input from ESPN analysts Trent Dilfer, Jon Gruden, and Ron Jaworski. Total QBR was developed based on analysis of 60,000 NFL plays between 2008 and 2010, and was unveiled on August 5, 2011. [4] The formula was modified in 2012 and again in 2013. [5] [6]

Characteristics

There are six steps to building QBR: [7]

Summary of computation

Raw QBR is calculated as the following:

,

where g() is a function that scales from 0-100, where 50 is average. Total QBR is the raw QBR adjusted for the strength of the opponent.

EPA is calculated based on the down, distance, and the yard line at snap, with each combination having its own point value. The point values are the average net point advantage the team on offense can expect given the particular down, distance, and field position. For example, a 1st and goal chance on the opponent's’ 1 yard line heavily favors the offense, yielding a positive point value. On the other hand, a 3rd and 9 on the team's own 3 yard line is heavily negative because it drastically favors the opponent.

The value of each play's outcome is measured by the snap-to-snap change in expected points. This is called Expected Points Added. The Expected Points Added (or lost) in each play are divided among the contributing players on the field based on the role of each player and the type of play. Deeper throws give a higher share of credit to the QB, while screen passes give relatively less credit to the QB and more to the receiver.

Plays that occur in “trash time” are discounted by as much as 30%. Trash time is measured based on the leverage of each play which is primarily a function of score, time, and field position. Important, critical plays that are likely to change the outcome have high leverage, while plays that occur after the game has largely been already decided have low leverage. QBR discounts low leverage plays, but does not boost credit for “clutch” plays.

After each play's Expected Points Added is adjusted for difficulty, division of credit, and trash time, it is averaged on a per play basis. This average is further adjusted to account for the strength of opponent. Performance against a stronger defense that tends to allow low adjusted EPA per play is adjusted upwards while performance against a weaker defense is adjusted downwards. The degree of adjustment is in direct proportion to the strength of the opponent.

Lastly, the resulting adjusted EPA per play is transformed to a 0 to 100 scale, where 50 is average. The result can be thought of as a percentile. For example, a QBR of 80 means that the QB's performance is better than 80% of the game performances by QB's since 2006. A game QBR of 80 would also mean that, given that QB's performance, his team would be expected to win that game on average 80% of the time. [8]

Comparison to NFL passer rating

According to ESPN, QBR is a more complete and meaningful alternative to the passer rating, which remains the official NFL measure of quarterback performance. The calculation of the NFL passer rating is much simpler than the QBR, as it depends only on passing statistics rather than an analysis of each play a quarterback is involved in. Because of this, some consider QBR to be a more holistic account of a quarterback's performance. [1]

The QBR calculation accounts for several meaningful statistics that are not included in passer rating, such as throwing distance, sacks, fumbles, designed runs and scrambles. QBR also makes adjustments for situational context with "EPA"—a dynamic statistic that is meant to signify "expected points added" per play. [1]

Example of Total QBR

Total QBR takes each individual play and measures the expected points added (EPA) for each play. Since every play situation is different, there is a different value for EPA in each case. A team can expect a 0.9 net-point advantage when it is 1st down and 10 yards to go on their own 20 yard line. For the next play, suppose the team passes the ball 8 yards to reach their own 28 yard line on 2nd down and 2. The offense can now expect a 1.4 net-point advantage. EPA is the difference in the expected points at the start and end of a play. In this case it is 1.4 - 0.9 = 0.5 EPA. In a way, the offense has added a half point in potential score based on this play. Similarly, if a team loses yardage on a play, their EPA in that situation would be negative.

Total QBR takes EPA and adjusts it based on the difficulty of the play. If a quarterback is under duress and avoids a sack to throw a 10-yard pass, Total QBR will reward the quarterback in those situations more than a 10-yard pass with much time to throw. In addition, it understands the importance of depth of target: the quarterback is rewarded more for a 40-yard pass compared to a 10-yard pass where the receiver ran for an extra 30 yards.

There is a discount on trash time. A 40-yard pass as time expires (without scoring a touchdown or field goal) is much different from a 40-yard pass with enough time to score points.

Total QBR takes into account the level of difficulty the opponent team's defense is based on the opponent's’ defensive FPI, among other factors.

Conceptualizing the detail Total QBR puts in can be explained through the 2015 NFC Wild Card game between the Green Bay Packers and the Washington Redskins. [9] Aaron Rodgers of the Packers completed 21 of 36 passes for 210 yards, 2 touchdowns, and 0 interceptions, which computes to a 93.5 passer rating. Kirk Cousins of the Redskins completed 29 of 46 passes for 329 yards with 1 touchdown and 0 interceptions, computing a 91.7 passer rating. Observing these statistics, one is likely to conclude that Cousins and Rodgers had similar success and that it was likely a close game. However, the Packers won, 35-18, and much of the reason for that can be attributed to Rodgers' overall play, not just his passing numbers.

Traditional passer statistics omit the rest of the impact that these quarterbacks made. Cousins also took 6 sacks, had 3 fumbles (1 lost), and 2 pre-snap penalties on Washington's offense. Rodgers, on the other hand, took only one sack, did not fumble, and drew a number of defensive penalties to keep drives alive. Rodgers manufactured five scoring drives, posting an 82.4 Total QBR. Cousins’ errors resulted in a Total QBR of just 58.9 and were a big factor in Washington losing the game.

Reception

Total QBR is a complex proprietary statistic that has led to questions on what values are being used and to what degree. The data obtained is from a video analyst tracking system instead of an eye test grading system, similar to a football scout.

Unlike the NFL passer rating, ESPN has not yet been forthcoming on the exact specific formulas and procedures to calculate QBR. [2] The proprietary, complex methodology spans some 10,000 lines of code. [10] 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." [11] [12]

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.". [13]

Michael David Smith of Profootballtalk.com explained the major drawback of QBR: [3]

One of the aspects of Total QBR that could be both a strength and a drawback is that it considers data that the average fan doesn’t have access to, like how far a pass travels in the air, and whether the quarterback was under pressure when he threw it ... it means fans can't see for themselves exactly where Total QBR comes from—fans just have to trust that the distance the ball traveled was correctly measured, and how much pressure the quarterback felt on the play was correctly assessed ... If ESPN is committed to this stat and is able to clearly and concisely explain it on the Worldwide Leader’s NFL broadcasts, then fans will quickly become familiar with it and it will soon become a staple of how we talk about quarterbacks. On the other hand, if the stat comes across as too convoluted — or if it doesn’t really seem like much of an improvement on the current passer rating — then this will all feel like a rather pointless exercise.

Further criticism of QBR was brought about when, before some tinkering with the equation of QBR, Pittsburgh Steelers quarterback Charlie Batch had the greatest individual game ever evaluated by QBR with a score of 99.9 against the Tampa Bay Buccaneers on September 26, 2010. Batch threw for 186 yards with three touchdowns and two interceptions in the game. He also ran five times for 26 yards. Statistics that helped Batch's QBR rise were that he was not sacked, did not fumble, and that he completed 70.6% of his passes, one of which he spiked into the ground to stop the clock. [14]

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. [15] 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 (i.e., 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 in 2011. 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. In a more recent example, a game played on September 24, 2017, Alex Smith of Kansas City Chiefs received an inexplicable QBR of 7.8, half as much as the equally-bad QBR of 16.1 for his counterpart Philip Rivers of the Los Angeles Chargers, even though Smith had a higher completion rate (16/21 vs. 20/40), a better average per completion (7.8 yds vs. 5.9), a far superior TD/int ratio (2-0 vs. 0-3), and won the game handily 24-10. For comparison, the RTG, 128.1 for Smith and 37.2 for Rivers, was by far a better metric of success. Mike Florio of Profootballtalk.com wrote that he'll "continue to ignore ESPN’s Total QBR stat." [16] 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." [17] 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. [18] [19] 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 rewarding Tebow because he came off the bench in the second half in an attempt to stage a comeback. [20]

NFL QBR records

Single-season QBR leaders

The following is a list of the ten all-time best single-season leaders of the QBR statistic in the NFL: [21]

RankSeasonPlayerQBRTeam
1. 2007 Tom Brady 88.2 New England Patriots
2. 2006 Peyton Manning 87.5 Indianapolis Colts
3. 2011 Aaron Rodgers 85.5 Green Bay Packers
4. 2020 Aaron Rodgers 84.4 Green Bay Packers
5. 2011 Drew Brees 84.3 New Orleans Saints
6. 2009 Drew Brees 84.2 New Orleans Saints
7. 2016 Matt Ryan 83.3 Atlanta Falcons
8. 2016 Tom Brady 83.0 New England Patriots
9. 2009 Peyton Manning 82.8 Indianapolis Colts
10. 2007 David Garrard 82.5 Jacksonville Jaguars

Season-by-season QBR leaders

The following is a list of the season-by-season leaders of the QBR statistic in the NFL: [22]

SeasonPlayerQBRTeam
2006 Peyton Manning 87.5 Indianapolis Colts
2007 Tom Brady 88.2 New England Patriots
2008 Peyton Manning 78.0 Indianapolis Colts
2009 Drew Brees 84.2 New Orleans Saints
2010 Tom Brady 81.3 New England Patriots
2011 Aaron Rodgers 85.5 Green Bay Packers
2012 Peyton Manning 81.3 Denver Broncos
2013 Peyton Manning 82.2 Denver Broncos
2014 Tony Romo 81.5 Dallas Cowboys
2015 Carson Palmer 78.6 Arizona Cardinals
2016 Matt Ryan 83.3 Atlanta Falcons
2017 Carson Wentz 74.4 Philadelphia Eagles
2018 Patrick Mahomes 81.8 Kansas City Chiefs
2019 Lamar Jackson 81.8 Baltimore Ravens
2020 Aaron Rodgers 84.4 Green Bay Packers
2021 Aaron Rodgers 69.1 Green Bay Packers
2022 Patrick Mahomes 77.6 Kansas City Chiefs

Related Research Articles

Passer rating is a measure of the performance of passers, primarily quarterbacks, in gridiron football. There are two formulas currently in use: one used by both the National Football League (NFL) and Canadian Football League (CFL), and the other used in NCAA football. Passer rating is calculated using a player's passing attempts, completions, yards, touchdowns, and interceptions. Passer rating in the NFL is on a scale from 0 to 158.3. Passing efficiency in college football is on a scale from −731.6 to 1261.6.

<span class="mw-page-title-main">Kyle Orton</span> American football player (born 1982)

Kyle Raymond Orton is a former American football quarterback. He played college football for Purdue, where he started four straight bowl games. He was drafted by the Chicago Bears in the fourth round of the 2005 NFL Draft. After an injury to Bears starter Rex Grossman, Orton was pressed into service as the starting quarterback during his rookie year, starting the first 14 games of the 2005 season, but was replaced by Grossman for the playoffs that year. Orton did not play at all in 2006, and sparingly in 2007. He regained his starting job from Grossman in 2008, but the team finished a disappointing 9–7 and out of the playoffs. In the offseason of that year, he was traded to the Denver Broncos.

<span class="mw-page-title-main">Aaron Rodgers</span> American football player (born 1983)

Aaron Charles Rodgers is an American football quarterback for the New York Jets of the National Football League (NFL). Rodgers began his college football career at Butte College in 2002 before transferring to University of California, Berkeley. With the California Golden Bears, he set several career passing records, including lowest single-season and career interception rates. He was selected in the first round of the 2005 NFL Draft by the Green Bay Packers and played for the Packers from 2005 to 2022. Rodgers is regarded amongst the greatest and most talented quarterbacks of all time.

<span class="mw-page-title-main">John Beck (gridiron football)</span> American football player and coach (born 1981)

John Dalton Beck is an American football coach and former quarterback who played in the National Football League (NFL) for 6 seasons. He played college football at Brigham Young University, and was drafted by the Miami Dolphins in the second round of the 2007 NFL Draft. In addition to the Dolphins, Beck played professionally for the NFL's Baltimore Ravens, Washington Redskins, and Houston Texans, as well as the BC Lions of the Canadian Football League.

<span class="mw-page-title-main">Frank Cignetti Jr.</span> American football coach (born 1965)

Frank Cignetti Jr. is an American football coach who is the offensive coordinator for the Pittsburgh Panthers. Before Pitt, he was the offensive coordinator at Boston College and the quarterbacks coach for the Green Bay Packers of the National Football League (NFL). He has also been the quarterbacks coach for the New York Giants in 2016 and 2017. Prior to that, he served as the quarterbacks coach for the St. Louis Rams from 2012 to 2014 and offensive coordinator for the Rams in 2015.

<span class="mw-page-title-main">Jimmy Clausen</span> American football player (born 1987)

James Richard Clausen is a former American football quarterback who played in the National Football League (NFL) from 2010 to 2015. He played college football at Notre Dame and was drafted by the Carolina Panthers in the second round of the 2010 NFL Draft.

<span class="mw-page-title-main">Sam Bradford</span> American football player (born 1987)

Samuel Jacob Bradford is an American former professional football player who was a quarterback for nine seasons in the National Football League (NFL), most notably with the St. Louis Rams and Minnesota Vikings. He was also a member of the Philadelphia Eagles and Arizona Cardinals. Bradford attended Putnam City North High School in Oklahoma City, where he starred in football, basketball and golf. As a senior quarterback in 2005, he threw for 2,029 yards and 17 touchdowns in 12 games. Bradford was not highly recruited coming out of high school, but he did receive a scholarship offer from the University of Oklahoma, which he accepted. After a redshirt season in 2006, Bradford threw for 3,121 yards and 36 touchdowns as a redshirt freshman with the Oklahoma Sooners. In 2008, Bradford became only the second sophomore to win the Heisman Trophy as he led the highest-scoring offense in NCAA history, passing for 4,720 yards with 50 touchdowns and just eight interceptions. He again led the nation in passing and also added five rushing touchdowns as the Sooners went 12–1 and advanced to the BCS national title game.

<span class="mw-page-title-main">Andy Dalton</span> American football player (born 1987)

Andrew Gregory Dalton is an American football quarterback for the Carolina Panthers of the National Football League (NFL). Nicknamed "Red Rifle", he previously played for the Cincinnati Bengals, Dallas Cowboys, Chicago Bears, and New Orleans Saints. Dalton played college football at Texas Christian University, where he became the school's leader in quarterback wins and won the 2011 Rose Bowl. He was selected by the Bengals in the second round of the 2011 NFL Draft.

<span class="mw-page-title-main">Tim Tebow</span> American football and baseball player (born 1987)

Timothy Richard Tebow is an American sports broadcaster and former football quarterback. Tebow played college football for the Florida Gators and became the first underclassman to win the Heisman Trophy in 2007. He was a key contributor to two BCS National Championship teams at Florida and was named the MVP of the 2009 BCS National Championship Game. As a dual-threat quarterback, Tebow broke numerous passing and rushing records during his collegiate career, among them Southeastern Conference (SEC) career records for highest passing efficiency rating and most rushing touchdowns and the NCAA record for most consecutive games in which he both passed and rushed for a touchdown.

<span class="mw-page-title-main">Christian Ponder</span> American football player (born 1988)

Christian Andrew Ponder is a former American football quarterback. He played for the Minnesota Vikings, Denver Broncos and San Francisco 49ers. He played college football at Florida State, and was drafted by the Minnesota Vikings with the 12th overall pick in the 2011 NFL Draft.

The 2011 NFL season was the 92nd regular season of the National Football League (NFL) and the 46th of the Super Bowl era. It began on Thursday, September 8, 2011, with the Super Bowl XLV champion Green Bay Packers defeating the Super Bowl XLIV champion New Orleans Saints at Lambeau Field and ended with Super Bowl XLVI, the league's championship game, on February 5, 2012, at Lucas Oil Stadium in Indianapolis where the New York Giants defeated the New England Patriots.

<span class="mw-page-title-main">2010 Green Bay Packers season</span> Season in franchise history

The 2010 Green Bay Packers season was the 92nd season overall and their 90th season in the National Football League (NFL). Although they finished with only a respectable 10–6 record, good for a second-place finish in the NFC North, the Packers never lost a game by more than four points, and never trailed by more than seven the entire season, becoming the only team since the AFL-NFL merger in 1970 to accomplish this. All six of their regular season losses were by a combined 20 points. They entered the playoffs as the NFC's sixth seed. After defeating the Philadelphia Eagles 21–16 in the wild-card round, the Atlanta Falcons 48–21 in the Divisional round, and long time rivals Chicago Bears 21–14 in the NFC Championship, the team advanced to Super Bowl XLV in which they faced the AFC's 2nd seed Pittsburgh Steelers. The Packers defeated the Steelers 31–25 to win their fourth Super Bowl and 13th NFL championship. The Packers became the second overall team after the 2005 Pittsburgh Steelers, and the first NFC team, to win the Super Bowl as a sixth seed, as well as becoming the second NFC team to win three straight road playoff games.

<span class="mw-page-title-main">Mike Kafka</span> American football player and coach (born 1987)

Michael John Kafka is an American football coach and former quarterback who is the offensive coordinator for the New York Giants of the National Football League (NFL). After attending St. Rita of Cascia High School in Chicago, Illinois, he played college football for Northwestern, where he received second-team All-Big Ten Conference honors as a senior. He was drafted by the Philadelphia Eagles in the fourth round of the 2010 NFL Draft, and spent six seasons in the NFL as a journeyman quarterback. Kafka became the quarterbacks coach for the Chiefs in 2018, and Patrick Mahomes, the starting quarterback for the Chiefs, earned the NFL Most Valuable Player award that season. Kafka helped the team win Super Bowl LIV the following season.

The 2011 Detroit Lions season was the franchise's 82nd season in the National Football League (NFL), their 78th as the Detroit Lions, the 10th playing its home games at Ford Field and the third year under head coach Jim Schwartz. With a regular season record of 10–6, the team improved on its 6–10 record from 2010, making it their third consecutive improved season. It was the Lions' first winning season since 2000 and first 10 win season since 1995. The Lions' 5–0 start was their best since 1956. With their win over the San Diego Chargers on December 24, the Lions clinched an NFC Wild Card spot in the postseason. After their loss to the Green Bay Packers in Week 17, it was determined the Lions would play the New Orleans Saints in one of the NFC Wild Card Games, which the Lions lost 45–28. It was their first playoff berth since 1999.

<span class="mw-page-title-main">2011 Green Bay Packers season</span> NFL team season

The 2011 Green Bay Packers season was the franchise's 93rd season overall and their 91st in the National Football League (NFL), and the sixth under head coach Mike McCarthy. The team not only improved on their 10–6 record from a season earlier, they became just the sixth team in NFL history to win 15 games during the regular season. As of 2022, the 15–1 record stands as the best in team history, as well as the best record for a defending Super Bowl champion. The Packers won their first 13 games of the season to extend their winning streak from the previous season to 19, the second-longest in NFL history behind the 21-game winning streak of the New England Patriots in 2003 and 2004, and also tied the record for the best start to a season in NFC history that the New Orleans Saints had set in 2009. The only loss for the Packers during the regular season was a Week 15 defeat in Arrowhead Stadium against the Kansas City Chiefs. They also became the first NFC North team to go undefeated in the division since the 1987 Chicago Bears.

<span class="mw-page-title-main">Zach Mettenberger</span> American football player (born 1991)

Zachary Rich Mettenberger is a former American football quarterback who played in the National Football League (NFL) for three seasons, primarily with the Tennessee Titans. He played college football at LSU and was selected by the Titans in the sixth round of the 2014 NFL Draft. After two seasons in Tennessee as a backup, Mettenberger had an offseason stint with the San Diego Chargers before spending his final NFL year as a backup for the Pittsburgh Steelers in 2016. Mettenberger last played professionally with the Memphis Express of the Alliance of American Football (AAF) in 2019. He began a coaching career the following year and has been an analyst for the University of Alabama since 2022.

<span class="mw-page-title-main">Patrick Mahomes</span> American football player (born 1995)

Patrick Lavon Mahomes II is an American football quarterback for the Kansas City Chiefs of the National Football League (NFL). The son of former Major League Baseball (MLB) pitcher Pat Mahomes, he played college football and baseball at Texas Tech. Following his sophomore year, he quit baseball to focus solely on football. In his junior year, he led all NCAA Division I FBS players in multiple categories including passing yards (5,052) and total touchdowns (53). He was selected 10th overall by the Kansas City Chiefs in the 2017 NFL Draft.

Football Power Index is a predictive rating system developed by ESPN that measures team strength and uses it to forecast game and season results in American football. Each team’s FPI rating is composed of predictive offensive, defensive, and special teams value, as measured by a function of expected points added (EPA). That rating is the basis for FPI’s game-level and season-level projections.

The Broncos–Steelers rivalry is a National Football League (NFL) rivalry between the Denver Broncos and the Pittsburgh Steelers. The rivalry stemmed from the eight playoff matchups between the two teams, some of which featured upset victories. Of the eight meetings, six resulted in the winner eventually advancing to the Super Bowl.

Drew Plitt is an American football quarterback for the Arlington Renegades of the XFL. He played college football at Ball State.

References

  1. 1 2 3 4 "How is Total QBR calculated? We explain our quarterback rating". September 8, 2016.
  2. 1 2 Ekstrom, Bob (August 10, 2011). "ESPN's Double-Secret QBR Still Shrouded in Mystery". Sports Central. Retrieved August 22, 2011. That's what ESPN has done ... keep it secret. No one can criticize a methodology they can't analyze.
  3. 1 2 Smith, Michael David (August 1, 2011). "ESPN tries to build a better quarterback rating". Profootballtalk.com. Retrieved August 22, 2011.
  4. Nwulu, Mac (August 2, 2011). "ESPN Introduces The Total Quarterback Rating". ESPN MediaZone. Retrieved March 20, 2017.
  5. "NFL - Total QBR gets minor modifications". Espn.go.com. September 4, 2012. Retrieved March 20, 2017.
  6. "NFL - Total QBR updates for 2013". Espn.go.com. September 5, 2013. Retrieved March 20, 2017.
  7. "How is a QB's efficiency rated? - ESPN Video". ESPN.com. Retrieved November 13, 2017.
  8. "Oliver: Guide to the Total Quarterback Rating". ESPN.com. Retrieved November 13, 2017.
  9. "How is Total QBR calculated? We explain our quarterback rating". ESPN.com. Retrieved November 13, 2017.
  10. Sando, Mike (August 1, 2011). "How to identify NFL's best quarterbacks". ESPN. Retrieved August 22, 2011.
  11. Farrar, Doug (August 17, 2011). "Philip Rivers at odds with ESPN's new quarterback ranking". Yahoo! Sports. Retrieved August 22, 2011.
  12. "Philip Rivers Doesn't Agree With Or Understand Total QBR". Deadspin. August 17, 2011. Retrieved August 22, 2011.
  13. "Total QB Rating: Everything Great About ESPN Multiplied By Everything Insufferable". Deadspin. August 10, 2011. Retrieved August 22, 2011.
  14. "Charlie Batch's 186-yard, two-pick game has ESPN's best QBR ever". November 19, 2015.
  15. Burke, Brian (August 12, 2011). "ESPN's New QB Stat". Advanced NFL Stats. Retrieved August 22, 2011.
  16. Florio, Mike (October 10, 2011). "ESPN's QBR stat puts Tebow ahead of Rodgers". Profootballtalk.com. Retrieved October 15, 2011.
  17. "Aaron Rodgers Chuckled After Learning that Tim Tebow Had Higher QBR". Larry Brown Sports. October 10, 2011. Retrieved October 15, 2011.
  18. "Tebow's diverse skills boost Total QBR". ESPN. October 11, 2011. Retrieved October 15, 2011.
  19. "Why QBR favored Tebow over Rodgers". ESPN. October 11, 2011. Retrieved October 15, 2011.
  20. Farrar, Doug (October 14, 2011). "ESPN's Total QBR stat makes as much sense to Aaron Rodgers as it does to me". Yahoo! Sports . Retrieved October 15, 2011.
  21. "NFL QBR Single-Season Leaders". Pro Football Reference. Sports-Reference . Retrieved February 14, 2018.
  22. "NFL QBR Year-by-Year Leaders". Pro Football Reference. Sports-Reference . Retrieved February 14, 2018.