digger

09-06-2012, 05:08 PM

http://www.grantland.com/story/_/id/8284393/breaking-best-nfl-stats

Football's Pythagorean Theorem

In a Sentence: Point differential is a better indicator of future winning percentage than winning percentage itself.

How It Works: Created by Bill James for baseball and modified for football in the early '90s by current Houston Rockets general manager Daryl Morey, the Pythagorean theorem (or "Pythagorean expectation") is a formula that translates a team's points scored and allowed into an "expected" winning percentage. That formula isn't exactly for the faint of heart:

Points For<sup>2.37</sup> / (Points For<sup>2.37</sup> + Points Against<sup>2.37</sup>)

As an example, let's take the 2011 Chiefs, who went 7-9 while scoring 212 points and allowing 338. Our formula is 212<sup>2.37</sup> / (212<sup>2.37</sup> + 338<sup>2.37</sup>) = 0.248. That's the Chiefs' expected winning percentage from their point differential, and if we multiply it by 16 games, we get a total of just 4.0 wins. The Pythagorean theorem suggests that the Chiefs outperformed their true level of performance by three full wins.

See we did better last year. :banghead:

Football's Pythagorean Theorem

In a Sentence: Point differential is a better indicator of future winning percentage than winning percentage itself.

How It Works: Created by Bill James for baseball and modified for football in the early '90s by current Houston Rockets general manager Daryl Morey, the Pythagorean theorem (or "Pythagorean expectation") is a formula that translates a team's points scored and allowed into an "expected" winning percentage. That formula isn't exactly for the faint of heart:

Points For<sup>2.37</sup> / (Points For<sup>2.37</sup> + Points Against<sup>2.37</sup>)

As an example, let's take the 2011 Chiefs, who went 7-9 while scoring 212 points and allowing 338. Our formula is 212<sup>2.37</sup> / (212<sup>2.37</sup> + 338<sup>2.37</sup>) = 0.248. That's the Chiefs' expected winning percentage from their point differential, and if we multiply it by 16 games, we get a total of just 4.0 wins. The Pythagorean theorem suggests that the Chiefs outperformed their true level of performance by three full wins.

See we did better last year. :banghead: