NFL QB Ratings

Factual Questions
1

  1. What is the precise formula for calculating quarterback ratings?

  2. What would be the QB rating of someone with a 100% completion rate, who throws each pass for a 99 yard touchdown? Is there anything that such a quarterback could do to raise their rating?

2

Here is the way the NFL calculates its Passer Ratings:

http://www.nfl.com/news/981202qbrate.html

also here (a bit past half-way down the page):

http://snap.stats.com/fenwaydir/stats/nfl/league/glossary.html

Here is a calculator that will work a rating out for you if you provide the necessary parameters:

http://www.football.com/cgi-bin/qbpassrating/index.shtml

3

Using Johnny’s calculator link, and figuring 15 attempts that all were completed for 99 yard touchdowns, you get a passer rating of 158.3. I vaguely remember reading that that is the theoretical maximum.

4

158.3 is indeed the maximum on the scale. If you go to a link where the formula is given, you’ll find that:

Completion percentages of 77.5% or more are equivalent
Touchdown percentages of 11.875% or more are equivalent
Yards/attempt of 12.50 or better are equivalent

For any given category (the fourth category is interceptions), one can earn no more than 2.375 points. You would then take the maximum number of points (2.375 * 4 = 9.5), divide by 6 (9.5/6 = 1.5833333), and multiply by 100, to get a maximum possible rating of 158.333

If we extend the formula so that 2.375 is no longer the maximum possible number of points (ignoring that we unbalance things by doing this), we’d get for your hypothetical situtation a rating of 831.25