Joel

12-11-2011, 10:55 AM

Not sure where to put this, but this makes more sense than any other option.

Part I: The PRS and Its Flaws

25(20Comp+Yds+80TD-100Int)+12.5/6

6Att

That's the critter, easily understood and far less mysteriously complicated than the NFLs "official" calculation, but results are identical for a "qualifying" numbers of throws (224, or 14/game.) Quarterbacks get:

20 points per completion, 1 point per yard, 80 points per TD and -100 points per interception. Divide by attempts, multiply by 25/6 and add 12.5/6.

If you're still here, congrats: You can now figure a passer rating, probably in your head (but maybe you already could.) A convenient example is Tim Tebows* 10/15 for 202 yds, 2 TDs and 0 Ints last week:

25(20*10+202+80*2-0)+12.5/6, or 25*562/90+12.5/6, which equals 14050/90+12.5/6

6*15

10 cancels out of the top and bottom (it's always wise to cancel when mentally figuring PRs) leaving 1405/9+12.5/6=158.1944....

Yet the NFL lists Tebows PR against Minnesota as 149.3; why? Because the Leagues official calculation sets upper and lower bounds for each category, bounding PR between 0 and 158.33... so it says ALL QBs have between:

0-77.5% completions, 0-12.5 YPA, 0-11.875% TDs and 0-9.5% Ints

In the case of Denver@Minnesota, Tebows 13.466... YPA and 13.33...% TDs greatly exceed the limits, so the League drops the excess. There are three equally negative consequences; the NFL PRS says:

1) A TD on every pass is no better than a TD every eighth pass,

2) An Int on every pass is no worse than an Int every tenth pass and

3) 50 YPA is no better than 12.5 YPA

Anyone agree? Didn't think so.

The upper and lower bounds are the first problem with the PRS, and probably the smallest; they can practically never affect season and career stats (but can and do skew game and partial season stats as demonstrated.) It's hard to appreciate without calculating a game rating around 400 only to hear announcers declare it a "perfect" 158.3, or calculating a rating in negative triple digits only to hear announcers mercifully declare it "zero." That's why Tebow had a 149.3 rating last week instead of 158.2, and why Craig Mortons rating for SB XII is 0 instead of -76.

Additionally, casual examination of the formula reveals what the NFLs official process obscures: According to the PRS, 5 completions=1 TD pass! 5*20=1*20+80, right? Perhaps worse, completing EVERY pass but LOSING yardage gets stellar ratings! (5*20-25)/5>(2*20+25)/5, right? Of course, the second guy's half a football field closer to the goal line, but don't let that distract you from the first guys better RATING. ;) People point to the West Coast offenses higher ratings as vindication of it, but the logic is rather circular: The PRS was practically DESIGNED for West Coast QBs; it rates them best because that's its job, not because they're the best. Some people even take THAT to vindicate the PRS BECAUSE it places "the best" (i.e. WC) QBs on top, leaving those of us with a basic grasp of logic pounding our skulls on our monitors (and wishing we could reach theirs.)

This has always been the thing I hate most about the NFL PRS: If Fran Tarkenton goes 6/20 for 200 yds, 2 TDs and 0 Ints while Joe Montana goes 15/20 for 100 yds, 1 TD and 0 Ints, they have the same rating. Tarkenton moving the Vikings twice as far and scoring twice as many points only (BARELY) makes up for Montana being more than twice as accurate. Or consider this: Take a 0 yd TD pass away from Tarkenton and his rating is WORSE than a guy who's 15/20 for -15 yds (which the PRS treats as 0 yds.) Compared to that, the PRS ignoring rushing is almost a trivial complaint (but only by comparison, hence I'll address it further down in the thread.)

*It is PURELY COINCIDENTAL that the PRS wrongly places the greatest value on Tim Tebows weakest quality while completely ignoring arguably his best ones. My own criticism of both flaws predates Tim Tebows very existence, and is itself the product of the same criticisms I first read about in The Hidden Game of Footballs chapter on "The Glory, the Blame and the Ratings." I STRONGLY advise anyone interested in a sound understanding of both the PRS and how the QB works in the NFL to read that chapter; reading the whole book would greatly improve most peoples grasp of NFL football in general.

Part I: The PRS and Its Flaws

25(20Comp+Yds+80TD-100Int)+12.5/6

6Att

That's the critter, easily understood and far less mysteriously complicated than the NFLs "official" calculation, but results are identical for a "qualifying" numbers of throws (224, or 14/game.) Quarterbacks get:

20 points per completion, 1 point per yard, 80 points per TD and -100 points per interception. Divide by attempts, multiply by 25/6 and add 12.5/6.

If you're still here, congrats: You can now figure a passer rating, probably in your head (but maybe you already could.) A convenient example is Tim Tebows* 10/15 for 202 yds, 2 TDs and 0 Ints last week:

25(20*10+202+80*2-0)+12.5/6, or 25*562/90+12.5/6, which equals 14050/90+12.5/6

6*15

10 cancels out of the top and bottom (it's always wise to cancel when mentally figuring PRs) leaving 1405/9+12.5/6=158.1944....

Yet the NFL lists Tebows PR against Minnesota as 149.3; why? Because the Leagues official calculation sets upper and lower bounds for each category, bounding PR between 0 and 158.33... so it says ALL QBs have between:

0-77.5% completions, 0-12.5 YPA, 0-11.875% TDs and 0-9.5% Ints

In the case of Denver@Minnesota, Tebows 13.466... YPA and 13.33...% TDs greatly exceed the limits, so the League drops the excess. There are three equally negative consequences; the NFL PRS says:

1) A TD on every pass is no better than a TD every eighth pass,

2) An Int on every pass is no worse than an Int every tenth pass and

3) 50 YPA is no better than 12.5 YPA

Anyone agree? Didn't think so.

The upper and lower bounds are the first problem with the PRS, and probably the smallest; they can practically never affect season and career stats (but can and do skew game and partial season stats as demonstrated.) It's hard to appreciate without calculating a game rating around 400 only to hear announcers declare it a "perfect" 158.3, or calculating a rating in negative triple digits only to hear announcers mercifully declare it "zero." That's why Tebow had a 149.3 rating last week instead of 158.2, and why Craig Mortons rating for SB XII is 0 instead of -76.

Additionally, casual examination of the formula reveals what the NFLs official process obscures: According to the PRS, 5 completions=1 TD pass! 5*20=1*20+80, right? Perhaps worse, completing EVERY pass but LOSING yardage gets stellar ratings! (5*20-25)/5>(2*20+25)/5, right? Of course, the second guy's half a football field closer to the goal line, but don't let that distract you from the first guys better RATING. ;) People point to the West Coast offenses higher ratings as vindication of it, but the logic is rather circular: The PRS was practically DESIGNED for West Coast QBs; it rates them best because that's its job, not because they're the best. Some people even take THAT to vindicate the PRS BECAUSE it places "the best" (i.e. WC) QBs on top, leaving those of us with a basic grasp of logic pounding our skulls on our monitors (and wishing we could reach theirs.)

This has always been the thing I hate most about the NFL PRS: If Fran Tarkenton goes 6/20 for 200 yds, 2 TDs and 0 Ints while Joe Montana goes 15/20 for 100 yds, 1 TD and 0 Ints, they have the same rating. Tarkenton moving the Vikings twice as far and scoring twice as many points only (BARELY) makes up for Montana being more than twice as accurate. Or consider this: Take a 0 yd TD pass away from Tarkenton and his rating is WORSE than a guy who's 15/20 for -15 yds (which the PRS treats as 0 yds.) Compared to that, the PRS ignoring rushing is almost a trivial complaint (but only by comparison, hence I'll address it further down in the thread.)

*It is PURELY COINCIDENTAL that the PRS wrongly places the greatest value on Tim Tebows weakest quality while completely ignoring arguably his best ones. My own criticism of both flaws predates Tim Tebows very existence, and is itself the product of the same criticisms I first read about in The Hidden Game of Footballs chapter on "The Glory, the Blame and the Ratings." I STRONGLY advise anyone interested in a sound understanding of both the PRS and how the QB works in the NFL to read that chapter; reading the whole book would greatly improve most peoples grasp of NFL football in general.