The Pi-Rate Ratings

August 25, 2010

Introducing the PiRate NFL Pass Rating Formula

Introducing the PiRate NFL Pass Rating Formula

 

The National Football League has been using the same pass rating formula for multiple decades.  It uses a combination of completion percentage, yards per attempt, touchdowns, and interceptions.  If you want to calculate it on your own, here it is:

 

I.     (Completion Percentage-30.0) * 0.05 +

II.    (Yards per attempt-3.0) * 0.25 +

III.   (20 * touchdowns per pass attempt) +

IV.   2.375 – (25 * interceptions per pass attempt)

 

If any of these four components are greater than 2.375, then cap the value at 2.375

 

Add these four stats together and multiple them by 16.667 to get the passer rating.  Here is an example:

 

In 1963, Y. A. Tittle had these stats for the New York Giants

Completions 221  Attempts 367  Yards 3145  Touchdowns 36  Interceptions 14

 

I.     (60.20 – 30.0) * 0.05 = 1.51  +

II.    (8.57-3.0) * 0.25 = 1.39        +

III.   (20 * .098) = 1.96                +

IV.   2.375 – (25 * .038) = 1.43    +

 

 Subtotal = 6.29     6.29 * 16.667 =

                     104.8

 

Once you know this formula, you can easily plug it into a spreadsheet and figure the ratings.  However, these ratings are a poor way to select the most efficient passer.

 

Let’s take a look at two opposing passers, Smith and Jones.

 

Smith completes 15 of 24 passes for 3 touchdowns with no interceptions.

 

Jones completes 10 of 24 passes for 0 touchdowns and 1 interception.

 

Smith is obviously much better, correct?  No, not correct.  It depends on several other things.  What if Jones has a lousy offensive line or receivers that drop every other pass thrown to them?  What if Smith has all day to pass with Jerry Rice-type receivers?  All these stats show us are just that—their stats.

 

Smith could have completed six passes to backs behind the line of scrimmage with the backs following blocking for long gains.  Jones could have threaded the needle with 30 yard passes to the deep sidelines only to have had them dropped by inept receivers.

 

In essence no pass-rating formula is worth a grain of salt.  Let’s look at two separate plays.  Passer A completes 13-yard pass for a touchdown.  It is a dump pass into the flat to the tailback with the tailback avoiding three defenders as he streaks into the end zone.  This one pass gets the NFL Maximum rating of 158.3.

 

Now, let’s look at Passer B.  His team is backed up at their own 1 yard line. He drops back and fires a bomb 55 yards through the air that comes down perfectly in the hands of his flanker.  The flanker takes off down the sideline and is knocked out just one yard from scoring.  This 98-yard pass gives Passer B a rating of 118.8!  Peyton Manning actually had a better total season rating than this a couple years ago, and even though he ranks among the best ever, he was not worth a 98-yard completion every time he threw the ball!

 

Can this be?  You betcha!  The rating is flawed.  Obviously the brilliantly thrown pass that travelled 55 yards past the line of scrimmage that comes down perfectly in the hands of the intended receiver should be worth a lot more than the dump pass that I could complete given two seconds protection.

 

Here is where the PiRate Pass Rating Formula tries to correct the incorrect values of the NFL Pass Rating Formula.

 

Our formula looks at just two statistics.  The first is interception percentage.  An intercepted pass is worth anywhere from 3 to 7 points for the other team on average.  We realize that all interceptions are not the same.  A poorly thrown pass into the flat at the offense’s 20-yard line hurts much more than a 3rd and 25 pass thrown 40 yards downfield and intercepted by the defense. 

 

The second stat is called “Air Yards Per Attempt,” or AYPA.  It is simply the passing yardage minus the yards after catch.  If Passer A completed a 51-yard pass for a touchdown, but the play consisted of a pass completed to a tailback one yard past the line of scrimmage with the back running for 50 yards, the passer gets credit for an AYPA of 1 yard (51 yard pass – 50 yards after the catch).

 

Here is the PiRate Pass Rating Formula:

[AYPA * 7 – (11 * Interception %) + 105] * 0.8

 Interception percentage is figured as: (Interceptions/Attempts) *100

 Anything over 100 is an excellent rating.  Over 90 means the QB is above average.  80 would be considered average; below 80 means this QB should be looking over his shoulder for a replacement to take his job.

 In our passer rating, we don’t include passing percentage or touchdown passes.  Yards gained are what matters.  Three consecutive completed passes that gain a total of nine yards means 4th & 1.  Two incomplete passes followed by an 11 yard completion means 1st & 10.  Which outcome is better?

 Touchdowns skew the ratings.  If one coach sends in passing plays at the opponents’ one yard line, while another sends his 240-pound power back to plunge over the goal, the quarterbacks will get too much credit in once instance and no credit in the other. 

 Let’s take a look at the PiRate Rating in action.  First, you must be wondering where can you find AYPA?  There is an excellent website that carries this stat, so you don’t have to try to figure out the YAC for each QB.  Go to: www.advancednflstats.com

 Here is a look at both ratings side-by-side:

Player

PiRate QB Rating

 

Player

Official NFL Rating

Aaron Rodgers

108.9

|||

Drew Brees

109.6

Drew Brees

107.5

|||

Brett Favre

107.2

Brett Favre

106.7

|||

Phil Rivers

104.4

Tony Romo

105.6

|||

Aaron Rodgers

103.2

Phil Rivers

104.8

|||

Ben Roethlisberger

100.5

Ben Roethlisberger

97.9

|||

Peyton Manning

99.9

Matt Schaub

97.8

|||

Matt Schaub

98.6

Peyton Manning

97.2

|||

Tony Romo

97.6

Donovan McNabb

96.3

|||

Tom Brady

96.2

David Garrard

96.1

|||

Kurt Warner

93.2

Kyle Orton

94.7

|||

Eli Manning

93.1

Brad Gradkowski

94.4

|||

Donovan McNabb

92.9

Tom Brady

93.8

|||

Joe Flacco

88.9

Kurt Warner

93.4

|||

Kyle Orton

86.8

Eli Manning

92.8

|||

Jason Campbell

86.4

Vince Young

92.1

|||

Carson Palmer

83.6

Joe Flacco

87.7

|||

David Garrard

83.5

Marc Bulger

86.7

|||

Vince Young

82.8

Jason Campbell

85.4

|||

Alex Smith

81.5

Matt Ryan

83.0

|||

Matt Ryan

80.9

Carson Palmer

81.7

|||

Brad Gradkowski

80.6

Chad Henne

80.8

|||

Jay Cutler

76.8

Alex Smith

79.7

|||

Chad Henne

75.2

Brady Quinn

78.4

|||

Matt Hasselbeck

75.1

Matt Hasselbeck

75.7

|||

Trent Edwards

73.8

Matt Cassel

75.7

|||

Marc Bulger

70.7

Kerry Collins

72.1

|||

Matt Cassel

69.9

Trent Edwards

69.9

|||

Ryan Fitzpatrick

69.7

Kyle Boller

69.1

|||

Brady Quinn

67.2

Jay Cutler

67.3

|||

Kerry Collins

65.5

Ryan Fitzpatrick

64.3

|||

Mark Sanchez

63.0

Mark Sanchez

60.9

|||

Kyle Boller

61.2

JaMarcus Russell

56.4

|||

Matt Stafford

61.0

Matt Stafford

54.1

|||

Josh Freeman

59.8

Jake Delhomme

51.5

|||

Jake Delhomme

59.4

Josh Freeman

46.4

|||

JaMarcus Russell

50.0

Derek Anderson

46.3

|||

Derek Anderson

42.1

 

Coming tomorrow: We reveal the initial NFL PiRate, Mean, and Bias ratings for the 2010 season and give our predictions for each division.

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