rhickok1109 wrote:Ronfitch wrote:rhickok1109 wrote:
I can't remember who did it, but I have seen a study using multiple regression analysis that showed a very strong correlation between "adjusted yards per pass attempt" and winning. The adjusted yards per pass attempt was calculated with this formula: AdjYards = (yards + 20 x TDs– 45 x INTs) / Attempts,
This?
http://www.footballperspective.com/nfl- ... k-13-2014/
It looks as if they're using the formula but I don't see the actual formula anywhere on that page.
They don't post it as a formula but rather write it out:
"... the NFL average Adjusted Net Yards per Attempt — defined as gross passing yards, plus 20 yards for every touchdown pass, minus 45 yards for every interception, and minus sack yards, all divided by the total number of pass attempts plus sacks ..."
So, their formula (or the one that someone else created and they use) would be:
Adjusted Net yards per Attempt = (passing yards + (20xTDs) - (45xINT) - sack yards) / (attempts + sacks)
I *think* - somebody check my work.
------------------------------
I found a copy of Berra's book, "Football by the Numbers 1986" in which he writes:
"We've used yards per pass as a basis for what we think is the single most important measure of a passing game's effectiveness, which I will call 'adjusted yards per pass.' What we've done is to subtract the sack yardage from the passing yards along with 50 yards for each interception thrown. Why 50 yards? To be entirely honest with you, the figure was part intuition and part guess. You have to figure that a team that doesn't throw an interception will have a chance on the next play to gain yardage, perhaps get a first down or even score. At the very least, a third- or fourth-down interception deprives a team of an opportunity to punt and put the opposition in poorer field position. On the other hand, some interceptions are as good as punts, or even better. There's simply no way to take it all into account and assign a precise value in yardage lost to interceptions, but years of studying the problem convinces us that 50 is a fair value. If any of you can come up with a more accurate number, please write us in care of our publisher and we'll try to make you famous. We really mean it: we welcome any and all comments on this."
So, Berra's formula (in 1986) is:
Adjusted yards per pass = (passing yards - sack yards + (50xInt)) / "passes"*
* He does not say whether a "pass" is a passing attempt or passing attempt + sack. He does include the "Adjusted Yards per Pass" stat for each team but does not include the numbers he used for each team to arrive at that so one could backward engineer it. For the '85 Packers, he writes:
"The Packers averaged only 6.95 yards per pass in 1985, which is just about the league mean. When you use our method and subtract the sack yardage and the 50-yard value for each interception, the Packers are down to 3.22."
Plugging in numbers for the '85 Packers on NFL.com (
https://www.nfl.com/stats/team-stats/of ... 85/reg/all), he was using sacks + pass attempts to define "passes" in his formula:
Adjusted yards per pass = (passing yards - sack yards + (50xInt)) / (attempts + sacks)
3.22025 = (3552 - 389 - (50x27)) / (513 + 50)
