Attention Bloggers: Win Probability Widget for 2011

If you run a website or blog, you can now include live win probability graphs on your own site. I've created a widget with some simple html code, and now it's available for all teams and all games.

Add the end of last season, I added another server that will handle a much greater traffic load. As regular visitors will attest, the demand for the live graphs would often crash the site, especially during nationally televised games. Hopefully, that's a thing of past. (The new link for live WP graphs is http://live.advancednflstats.com, but the old link will still work too.)

The WP widget is just like the smaller version of the graph I show on my main page during live games. Just add the following html snippet to your site.

<iframe width="500" height="450" scrolling="no" frameborder="0" src="http://live.advancednflstats.com/featureGraph.php?team=GB" name="game" ></iframe>

Chose which team's game you want to show, and replace the bit that says ?team=GB with ?team=PIT or ...=BLT or ...=SEA or whichever team's abbreviation you like. That team's current or most recent game will automatically appear. This way, you won't have to update the code snippet each week. If you run a Jaguars fan site, just leave it at ?team=JAX all season.

Advanced Box Scores

I teased this last week, and now the switch has been flipped. All final Win Probability graphs now include individual player advanced stat box scores.

They're better seen than described, so go ahead and check out last year's Super Bowl.

For each team, I've included the top 2 QBs, top 3 RBs, top 5 WRs/TEs, and top 7 defenders in terms of WPA to be included. Advanced stats for the full team can be seen by clicking on the Team Offense or Team Defense table headers. Due to space limitations, I had to decide which stats to include, so I focused on the ones that you don't tend to see other places--things like targets for WRs.

So get to it:

Call for Writers for 2011

This is probably long overdue, but I’m excited to announce that Advanced NFL Stats is planning to add a small number of contributors this season. I already have a couple writers lined up, and I’m looking for a limited number of additional smart, analytical thinkers to bring a fresh perspective to the world of NFL stats. Previous analytic or blogging experience is preferred, but not required.

Those interested should email me directly (see the About - Contact/FAQ menu link) with an introduction and links or attachments of 2 or more examples of your analysis and writing. If you have no previous experience, you can send ‘demo’ drafts of the kind of stuff you’d like to do.

In particular, I’m looking for contributors to ‘own’ a regular weekly assignment. For example (these are just random thoughts off the top of my head):

How Many Wins Is Manning Really Worth?

It seems that's the big question lately, with Peyton Manning doubtful for Sunday as he rehabilitates his neck. The football punditeratti say there is no other individual player so critical to his team's success than Manning, and they're probably correct.

Win Probability Added (WPA) can't do everything, but one of the things it can do extremely well is tell us exactly how much of every win or loss was due to one component of a team. In this case, it can tell us how many wins the Peyton Manning passing game can account for. Although we can't really separate Manning from his blockers and receivers, we can nail down a hard number for the Colts passing game as a whole, of which Manning has been the central fixture.

Since 2000 (as far back as my data goes), Manning played in 176 regular-season games and accumulated a total of 43.0 WPA, for an average of 3.8 WPA per season. This equates to 0.24 WPA per game, which means that Manning (and his passing offense) would give an otherwise perfectly average team a 74% chance of winning a game. In other words, he would take an 8-win team and make them an 11.8-win team.

How Quarterbacks Age

Peyton Manning signed a $90 million contract extension that would hypothetically keep him playing through age 40. Nagging questions about his health will almost certainly plague him for the remaining years of his career. To back up the ailing Manning, the Colts brought in an even older veteran passer, Kerry Collins. In Philadelphia, Michael Vick signed a $100 million contract that will supposedly keep him playing until he's 37. What kind of performance should we expect from older passers?

It's a much more difficult question than it first seems. Averaging the performance of all the recent QBs by age doesn't work. A survivor bias ensures that only the successful QBs stay in the league long enough to have their stats in the sample. Another complication is the the steady inflation of passing stats over the years. In this post, I'll try to tackle those problems to better understand how QB performance is affected by age.

New Game WP Pages

Here's a quick look at a work in progress. It's a redesigned WP Graph page with advanced player stats. It's not done, but it should be ready for the beginning of the season.

Don't Pay CJ!

The word is that Chris Johnson won't be satisfied with being the highest paid RB in the league. He wants to be among the highest paid players at any position. With Larry Fitzgerald's recent 8-year deal guaranteeing nearly $50 million, Johnson must be thinking he's worth something similar. Peyton Manning's recent contract will pay him nearly $20 million per year, and it might make sense to pay one of the greatest QBs of all time 1/6 of your entire payroll. But paying that kind of money to any RB, even the very best, makes no sense.

Adrian Peterson is currently the highest paid RB who is due to make $11 million this season, which is probably two to three times too much. RBs, and the running game in general, do not have the impact on wins and losses the same way the passing game does. But more importantly, the spread between the best and the mediocre RBs is much smaller than the the spread among quarterbacks.

We can't quantify the value of a player the way the MLB analysts can, with Wins Above Replacement and other stats. But we can at least make some back-of-the-envelope, order-of-magnitude estimates.

ESPN's New QB Stat

I, for one, welcome our new statistical overlords.

ESPN has a talented new analytics team, and their first foray into football is their Total QB Rating. It seems the first thing anyone does when they get into advanced football stats is to create their own QB rating system. The QBR is a major improvement over the NFL's traditional passer rating, and there are a lot of things I like about it, but it's not perfect. I'll try to summarize my understanding of the stat, and then I'll list the things I like about it and the things I don't like so much. As we say in the fighter pilot business--the goods and others.

According to ESPN's own explanation, the stat is based on three primary concepts--Expected Points, Win Probability, and division of credit. As I understand it, QBR begins with a QB's Expected Points Added for each play in which he was directly involved, including both pass plays and runs. It modifies each play's EPA value according to a clutch factor, which is based on Win Probability (WP). Here, I use something similar known as Leverage Index (LI). LI is the ratio of the potential swing in WP for a play compared to the average play's potential swing in WP. For example, an LI of 3 means that a play is 3 times more critical to a game's outcome than the typical NFL play. (You can find any play's LI on the interactive WP graphs here by hovering your cursor over the graph. I still consider it a 'beta' stat because I haven't settled on a final, single definition of potential success and failure for every play.)