For Nerds. Stats and Football

From the mind of LYSB co-host,  Aaron Close, TexansBroncos.

Ok first let me apologize for the content of this article right up front.  I know a lot of you are not math/science people so this will get a bit on the boring side for you but it interests me and I’m sure one other person on planet earth so here goes.

First my goal was to get a sense of what the outcome of the NFL regular season might look like by the end of the year.  This is not an easy thing to do, several other groups out there do the same thing I do in different ways, they try to model the difference from year to year based on personnel changes and what not.  So let me tell you how I did it.. First I started with last year’s performance during the regular season and looked at each teams game to game variance (in English that means how consistent was their defense and offence) along with their whole year performance in terms of points scored and points given up.  Then I look at changes over the off-season to try to determine how much better/worse each unit of each team might be.  This is not very scientific at all but has to be done somehow.  The player adjustments are pretty straight forward but the coaching adjustments are very unpredictable.  Like the effect a coaching change had on San Francisco last year.

So here is my table of each team’s basic information

Most of this should look pretty familiar to you until you get to about half way across the table.  This is where the stats kick in.  First there are two columns for Adjustments these are where I adjust last year’s performance based on changes in the off season negative numbers are negative effects on either Offensive performance or defensive performance.  A great example of this is if you look at the New Orleans Saints who have had a very rough off season I adjust last year’s offensive performance down by 50 points over the course of the year and the defensive performance down 70 points over the course of the year.  I also adjust other teams up for instance I add 100 points to the Broncos offence over the year just based on having Manning vs Tebow.  This is by far the most subjective part of the whole exercise but has to be done somehow.

Now to do a couple of adjustments to the base data, firs is the home field advantage.  There are several good studies out there that say the home field advantage is roughly 3 points per game.  (though it is less early in the season and more toward the end).  So I included this, I also included a higher variance (randomness) to games between division rivals so as those games seem to be more unpredictable than the ones between none division opponents.

Finally based on all of this information, I modeled each game of the season 100 times, and summed up the results.  This accounts for each team’s offence, defense, division differences, and home field advantages.  There are some things that surprised me and some things that where an utter yawn.

First Surprises

I find it very unlikely that the Giants will repeat, in fact most of my models don’t even have them making the playoffs.  The NFC looks tough this year and in 65% of my models the Eagles win the NFC East.

New Orleans still makes the play offs in over 60% of my models, in spite of the heavy whack I gave them both defensively and offensively in my projections.

Also I have San Diego winning the AFC West in about 55% of my models, and this is after giving Denver a lot of credit for Peyton Manning (100 points over the year) that’s about 7 points a game, just for one man.

Now the Yawns.

New England, Green Bay, and San Fran are likely to continue to be very good and I have them ranked 1,2, and 3 respectively at the end of the season.  With Green Bay and San Francisco getting the first round byes in the NFC and New England and your Houston Texans getting first round byes in the AFC.

The Playoff field on average stands like this

AFC Seeds

1.  New England with 11.47 wins on average (WOA)
2.  Houston 10.32 WOA
3.  Pittsburg 9.72 WOA
4.  San Diego 8.64 WOA
5.  Baltimore 9.66 WOA (wild card #1)
6.  Miami 8.54 WOA (wild card #2)

Missed playoffs

Denver 8.39 WOA

Cincinnati 8.29 WOA

Jets 8.26 WOA

Bills 7.94 WOA

NFC Seeds

1. Green Bay 11.39 WOA
2. San Francisco 11.31 WOA
3. Philadelphia 10.38 WOA
4. New Orleans 9.47 WOA
5. Detroit 9.59 WOA (wild card #1)
6. Atlanta 9.11 WOA (wild card #2)

Missed playoffs

Chicago 9.03 WOA

NY Giants 8.69 WOA

Carolina 7.94 WOA

Your Houston Texans seem to be virtual locks to win the division winning it an astounding 69% of the time.  In addition it is virtually impossible to model them to win less than 5 games during the season.  With only 5% of my models having 7 or less wins.  Also given their relatively tough schedule it is hard for them to get more than 12 wins with only a 9% chance of exceeding that mark.

The Chart below shows the results of all models run.

In addition this is a summary table of all of my model runs.