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.