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Dr. Z on Passer Ratings

Discussion in 'PatsFans.com - Patriots Fan Forum' started by FlyingElvis75, Oct 25, 2007.

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  1. FlyingElvis75

    FlyingElvis75 Rookie

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    http://sportsillustrated.cnn.com/2007/writers/dr_z/10/25/rating.system/index.html

    I'm not sure I agree with all his points, but I've been a huge detractor of the passer rating system ever since I understood how it was calculated. It's a relic, and not a useful one at that.

    Check out this example (which I also mailed to him):

    Quarterback A completes 46 of 47 passes for 575 yards. He throws 8 touchdowns. His lone incompletion is an interception.

    Quarterback B goes 12/15, throws for only 188 yards, gets 2 TDs and no interceptions.

    All else being equal, including team defense and special teams, which QB do you think would win the game? Which would you rather have? Which do you think had the better PASSING performance?

    Quarterback A, who would set single-game records for completions, completion percentage, passing yards, and touchdowns, would end up with a passer rating of 148.4 Quarterback B would have a perfect rating of 158.3.

    That's right - you don't need to even throw for 200 yards to get a perfect passer rating for the game in the books (NFL requires 14 attemps/game to qualify). And if you break every major single-game record, you can end up with a non-perfect rating if you throw just ONE interception.
  2. Nordy

    Nordy Rookie

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    The stuff about Elias refusing to even consider changing the way some stats are handled and the NFL front office continually not even caring to listen was REALLY interesting. I have to admit, Dr. Z wrote a good article here.
  3. FreakGoDeep

    FreakGoDeep Rookie

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    passer rating is not that bad.

    it's based on 4 things and calculated from your attempted passes.

    completions.
    yards
    TDs
    INTs.


    there is a max score on each catergory so this way if you throw 2 INTs you can't mask it by throwing for 500 yards or completing 50 passes.

    there are down sides to it. If a qb is throwing great in a game. yards, completions and no INTs but he's not getting TDs because he has a great running back that can pound it in...well his rating would suffer a little because of that.
    Last edited: Oct 25, 2007
  4. FlyingElvis75

    FlyingElvis75 Rookie

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    I know how passer rating is calculated, as I mentioned in the original post.

    My point is that it's not a helpful indicator of passing performance if it doesn't actually tell you who's the better passer. A big part of that is the "capping" on each factor, in my opinion.
  5. xmarkd400x

    xmarkd400x Rookie

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    While the statistic may noy in and of itself stand up to subjective tests (IE. which QB had the better day?) I would like to ask this: Does a higher passer rating correlate with more wins? If so, I say it is a decent statistic. It may not be the best.

    In general, better passer rating means better QB. I'm kind of rambling but yeah. I don't mind it as a statistic. Its not super duper but its serviceable.
  6. BradyManny

    BradyManny Rookie

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    Why write a negative article about passer ratings now I wonder? :rolleyes:
  7. Imperator

    Imperator Rookie

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    Last edited: Oct 25, 2007
  8. FlyingElvis75

    FlyingElvis75 Rookie

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    I'd say that's silly, since wins are dependent on far, far more than passing performance. In any case, PR isn't meant to assess team winning ability - it's meant to assess passing performance.

    [Edit] The examples I posted above aren't exactly subjective, either. 575 yards > 188 yards, obviously; 97.9% > 80%; 8 TDs > 2 TDs.

    From a scoring standpoint, 1 INT is at worst -2 TDs, i.e. you lose a touchdown you may have scored without the INT, and the opposition scores off your INT. In the worst case, then, 3 TDs + 1 INT = 1 TD. So, even in the worst possible case, 8 TDs + 1 INT > 2 TDs.
    Last edited: Oct 25, 2007
  9. FlyingElvis75

    FlyingElvis75 Rookie

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    Hehe. Good point. I question the timing, but agree with the content. :)
  10. TomBrady'sGoat

    TomBrady'sGoat Rookie

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    I already knew passer rating was a crappy stat. I didn't know it was based on 1973 standards. That's ridiculous.

    It is useful for the extremes. If a guy has a rating >100 you know he had a good game, while a rating <50 tells you he had a crappy game.

    It's of little usefulness when comparing similar QBs or when the rating falls somewhere in the 70-90 range.
  11. Oswlek

    Oswlek Rookie

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    Some addition passer rating issues:

    * A QB that takes a sack rather than throw it away is treated favorably.

    * Rushing is totally excluded (passer ratings)

    * TDs are given far too much weight. If two QBs have equal supporting parts, and both pass for 18/24 for 240 yards on non-TD passes, but one team decides to run in their two one yard TDs and the other decides to pass, the one who ends up with the TDs is rated 25 points higher.

    The sack/throwaway one is the one that bothers me the most.
  12. FlyingElvis75

    FlyingElvis75 Rookie

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    Agreed, but what bothers me most is that the system itself produces what looks like an objective number, but the factors that go into them are extremely subjective. They're based on what was considered almost unattainable in 1973 - 77.5% completion, 12.5 yards per attempt, 1 TD about every 8 or 9 attempts. Anything better than that is completely ignored...and those numbers are completely arbitrary, based only on the "sense" of a few key people in 1973.
  13. godef

    godef Rookie

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    Just one point...

    • Granted, QA had a great game and this should be reflected in a better rating. However, the rating he did get will carry much greater weight forward. The 12/15 performance of the other QB will not add much to his yearly rating.
  14. FlyingElvis75

    FlyingElvis75 Rookie

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    Yeah...QB A could have thrown 12/15 for the same yardage and TDs and still ended up with the lower rating, though. PR is probably better long-term than single game, just like most stats, but it doesn't erase the arbitrary and outdated "caps" and (in my opinion) extreme overweighting of INTs.

    Anyway...another baffling thing is the cap of 158.3, when they literally could have picked any other number as the max.
  15. Lampshade

    Lampshade Rookie

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    It's definitely silly to use it as the ultimate guide of QB play. Apparently 11 yards on 3rd and 15 is more valuable than 5 yards on 3rd and 4.
  16. hughthehand

    hughthehand Rookie

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    Passer Rating was designed to measure QB stats for the entire season, not a single game.

    So yes, your example is correct, QB rating is very flawed for a single game performance.

    When a QB, like Brady last week, has a max QB rating for a single game, it doesnt change the impact for the season Rating. Unless a QB has a perfect QB rating for the season, which is just about impossible, every stat for the game increases his season QB rating, regardless if his game rating tops out at 158.3.

    So as a previous poster said, QB A's game Has a greater impact to his Season QB rating than Passer B, even though Passer B's rating was higher for the single game.
  17. RayClay

    RayClay Rookie

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    #75 Jersey

    Why did that thought immediately occur to me too?:D
  18. solman

    solman Rookie

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    I think that passer rating is an effective way of comparing QB performance.

    Let me put it another, more quantitative way:

    Suppose you assembled a committee of nine coaches. Suppose you randomly selected 100 pairs of QBs who played in the same season (for each pair), provided all statistical information to those coaches (including each play of each drive) from that season, but hid the name and team of the QB.

    Suppose that any coach who recognized a QB recused himself from the deliberations, and that ties were broken by a coin flip.

    I would bet that for over 95% of the QB pairs, the coaches would agree with passer rating. It wouldn't shock me at all if this worked for 98 out of 100 pairs.

    Its easy to manufacture counter examples. Its especially easy to take statistics from a single game, and show that during that one game the stats were unreasonable.

    But over the course of a season (which is the period of time that passer rating was designed for) passer rating is an extremely effective gage of which passers performed better.

    The key inadequacies (adjusting the other players on your team) can't be handled effectively using statistics (and are widely accepted with other statistics and in other sports).

    At a minimum, I don't think that a substantially more accurate statistical measure can be created without making it substantially more complicated.
  19. Zeus

    Zeus PatsFans.com Supporter PatsFans.com Supporter

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  20. PonyExpress

    PonyExpress Rookie

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    I've been reading Dr. Z since I was a kid. He was probably the most famous and influential football writer in America. I still enjoy his annual All-pro columns. But he is committing the most grievous of all sportswriter sins: He has become boring. He's now Dr. Zzzzzzzzz.

    If the current system is broke, I know one thing: Dr. Z's ideas to repair it are almost certainly wrong.
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