I'm preparing to move the site to a new platform. Within a day or so the site will be hosted on a new content management system, which will allow us much more flexibility with all the new tools and content coming this season. I'm not sure how smooth the transition will be, so please stay tuned via Twitter in case things get broken over the next couple days.
With the url (web address) change earlier this year and now this change, I've completely destroyed the site's search rankings (which were really good), links, and 7 years of goodwill. I apologize.
To fix things, I'll need your help. Please update your links to the site's url and, more importantly, spread the word. Hopefully you've enjoyed reading the posts or using the other features at AFA over the past several years. I haven't asked much in return, so please give the site a shout out on Twitter, your own site, or whatever platform you have.
Just to be perfectly clear, here are how things are changing:
1. The new site will offer all the same content you've come to expect, including analysis, tools, live WP graphs, advanced stats, the podcast, advanced boxscores, and visualizations. In addition, it will have a separate section for team clients and media outlets who use AFA services.
2. The web address will continue to be www.advancedFootballAnalytics.com.
3. The twitter handle will remain @Adv_NFL_Stats.
4. The site's feed will change to http://www.advancedfootballanalytics.com/index.php?format=feed&type=rss (or ...&type=atom, depending on your preference.)
5. The podcast feed will continue to be http://advancednflstats.libsyn.com/rss
6. For now, older content will continue to be hosted at archive.advancedFootballAnalytics.com.
For the month of October I'll be celebrating the re-launch of the site with a feature of the day, highlighting many of the most popular things the site has to offer.
Big Changes Coming
Weekly Game Probabilities: A New Home
For now the score predictions are simply maximum-plausibility estimates. (Yes, I just made that term up.) Predicting an actual score for each game is statistically boring. With few exceptions, a statistically sound estimate would be 24-20 or 27-21 for every game, so I've added some of the human element to the score predictions. The bottom line is that readers should focus on the probabilities and don't bet the mortgage on the scores.
The game probabilities will be matched up against the picks of Will Lietch, one of the cornerstone writers at SOE. The idea is to create a friendly competition between man and machine.
The game probabilities had a great run at the New York Times--5 years. But there are only so many thought-provoking or counter-intuitive lessons on probabilities and predictions that can be squeezed out of a week of NFL games. But AFA will continue working with the Times on various projects as the season unfolds.
Here's the link to the probabilities for week one. For those keeping score at home, I had the Seahawks at 66% to win last night.
ANS Is Hiring!
The main responsibilities of the intern will include, but are not limited to the following:
*Support ANS team with data extractions, analysis, reporting, and data presentation
*Suggest new ways to improve existing processes
*Document and automate data and analytic processes
Required Qualifications
*Currently enrolled in, or a recent graduate of, a quantitative degree program such as Operations Research, Mathematics, Statistics, Economics, Computer Science, Information Science, Management Information Systems, or similar
*Senior, recent graduate or post-grad level
*Demonstrated attentiveness to detail
*Experience in analytical field
*Proficient in SPSS, SAS, mySQL, and/or R
*Proficient in Microsoft Office suite
Preferred Qualifications
Best of 2013
This is my favorite post of the year. It's an annual opportunity to look back over all the interesting analysis, features, visualizations, and analytical tools we've been able to put together at ANS. Great thanks to Keith Goldner, Dave Collins, Sterling Xie, Rob Hendryx, and Kevin Meers for making 2013 another successful year. (Here are the best-of posts of 2009, 2010, 2011, and 2012. They're a great way for new readers to come up to speed.)
I said this last year and I'll say it again. With each passing season I start to feel like we've peaked. Maybe all the low-hanging fruit of football analytics has been plucked, and there's little left to do but become a broken record on a handful of subjects. But this stuff is too much fun to give up. And so sure enough, over the course of another season we stumble on a few more insights and push the envelope just a little further. And interest continues to grow too. 2013 was the best year yet in terms of traffic to the site, and December was the site's best month ever.
With every new feature, ANS becomes a little bit harder to run throughout the season. So please forgive me as I take a breath, step back and highlight some of what we consider some of our favorite stuff. Of our 219 total posts in 2013, here are a few of the best...
With the AFC playoffs appearing to go through Denver throughout last January, I took a look at the effects of altitude on FG success.
Keith analyzed John Fox's decisions in his team's upset at the hands of the Ravens. Here are my own two cents in a post at Slate and Deadspin.
I finished up the series on when to intentionally allow a TD with a look at what the numbers say for when teams are tied. This was possibly the most challenging bit of analysis I've done, and it spawned the time calculator tool, which got a major upgrade last January.
I took a look at how much QB clutch performance persists from season to season.
February started with a look at how Joe Flacco's magical post-season over-performance compared to that of other QBs in the recent past.
The Super Bowl was one of the more interesting and exciting championship games in memory. It featured a fake punt, an intentional safety, and a couple crucial 4th down decisions. It was also a case study in saving your timeouts.
Win Probability Model/Calculator Upgrades - Team Strength Adjustment & More
I just implemented several new features and significant upgrades to the Win Probability Calculator tool as well as the model behind it.
1. The biggest new feature is the capability to adjust the WP estimates based on relative team strength. This is accomplished by entering either a pregame WP estimate from the efficiency model, another source, or the game's point spread. The model has had this ability for a long time, but I didn't want to implement it until I had a sound way of doing so.
The prior pregame estimate of WP is revised as the game goes on with the baseline in-game WP estimate. The two probabilities are reconciled using the logit method. The trick is to understand how the pregame difference in team strength decays over the course of the game. At a certain point, it doesn't matter how much a team was favored if it's trailing by two or more scores late in the game. Team strength differential decays proportionally to the log of time as the game progresses according to a particular curve.
Pregame WP or spreads should be with respect to the current offense. For example, if the game's spread was -3 but the visitor has the ball in the scenario you are investigating, enter 3 for the spread. In what is a cool enough feature all by itself, entering a spread will automatically convert into a pregame WP estimate.
For the record, the WPA stats for teams and players will continue to use the baseline unadjusted WP numbers. If we used the adjusted WP numbers, every team and player would have a zero WPA assuming our pregame estimates were accurate. Put simply, using the adjusted WPA stats would defeat their very purpose and only be a measure of how good our pregame forecasts were.
2. The next most significant update is the ability to account for receiving the kickoff in the 2nd half. This can have an effect of up to a 0.04 WP swing in the first half of close games. The input asks users for whether the team with possession kicked off to start the first half or not. This consideration doesn't apply following the 2nd half kickoff, so for 2nd half scenarios you can just leave the input at the default Don't Know.
New Feature: The NYT 4th Down Bot
In partnership with the New York Times, I'm pleased to unveil the bane of every football coach in America--The 4th Down Bot. At its heart, it is a real-time application of the 4th Down Calculator feature here at ANS. It uses both the Expected Points model and the Win Probability model to estimate the best option for every 4th down as a game is in progress.
Play-by-Play Data Update
Win Probability Calculator Upgrade - New OT Rules
After the MIN-GB overtime game Sunday, you may have stopped by the Win Probability Calculator tool to see what GB should have done on 4th down on the goal line on their first possession. As luck would have it, I rolled out a big upgrade to the calculator just the night before that incorporates the three various game states in overtime.
Under the 'Period' input, there are the 4 quarters, plus 3 overtime states, corresponding to:
-'First possession', in which a team can score a TD to win or a FG to begin...
-'Down by three', in which a team has all 4 downs to move down the field to win with a TD or match the FG to begin...
-'Sudden death', which begins upon any change of possession with a tie score.
The previous version of the calculator still relied on the old pure-sudden-death overtime format. With so few examples to test against, I'm sure there are a few bugs or discontinuities waiting to surprise us, so please note any discrepancies in the comments here. But remember that not all unexpected results are errors--The new format does have its quirks.
The new overtime model has already been working for the WP graphs and team/player stats. Soon I'll roll it out for the 4th Down Calculator too. And more big upgrades to the WP calculator tool are on their way.
Good News for Hipsters and Grandmothers
You've probably noticed that on your iPad the ANS front page presented you with a big white box with nothing but a line of text. It told you that you don't have Flash, and here's a link to a non-Flash version of the graph. And the link did nothing but take you to another page that told you the same thing and gave you the same link, which finally took you to the old pre-Flash version (which was optimized for circa-2008 Blackberrys.) Embarrassing.
But now things are looking up for you. Unfortunately I can't do anything about the hipster thing--you'll grow out of it eventually. But I can make it a lot easier to see live WP updates without Flash. Starting this weekend I've gotten off my butt and replaced the ugly 'You don't have Flash' error with the Apple-friendly version of the graph. This version isn't interactive and doesn't provide enhanced details, so it won't exactly knock your fedora off, but it's better than a big white box with an error message.
We're Gonna Party...
It's great to have the season included for a few reasons. Now we get to see the offensive output of the '99 Rams--The Greatest Show on Turf. I was actually surprised that their EPA totals weren't higher. It was also the first season of the reconstituted Browns franchise, and 1999 was Peyton Manning's first winning season, leading the Colts to a 13-3 record in his second year.
We also get to see the full careers of guys like:
Update to the Top Game Finder
I got the same unusual request from two separate people 10 minutes apart last night. Each one wrote that they and their wife watch NFL Game Rewind during the week, and they use the Top Game Finder to see which games are worth watching. (Yes, I asked to make sure it wasn't the same guy writing twice.) The problem is that the Finder results include each team's score, spoiling the game. One of the requests noted that he and his wife take turns using the Finder so the other one won't know the outcomes of the games they watch.
The request was to build a version of the tool that would not reveal the game outcome. That was easy enough, so if that's something others would be interested in, here is the link. (Note the address simply appends NoScore to the usual filename.)
http://wp.advancednflstats.com/greatgamesNoScore.php
As a bonus I thought it would be useful to include a Week field in the search bar. Unless one of the games during the recent week pops up as a game with an exceptionally high Excitement Index, you'd have to search team by team within a season to identify the best games of the week. Now you can enter the most recent week in the dropdown menu and get a list of that week's games sorted according to EI or Comeback Factor. And if you'd like to know the most exciting game of Week 6 of the 2004 season, it's at your fingertips. (STL 28 TB 21.) I've added this to both the normal tool and the score-free version.
A Plug for the Community Site
Let's face it. The world of football analytics has changed greatly over the years since Advanced NFL Stats broke ground on its multi-million dollar research complex in 2006. These days, a small portion of analytics is being done outside of the paradise-like garden of forward-thinking that is ANS. I've been told that up to one, possibly two percent of football research is being done elsewhere. Hard to believe, but it's true.
That's where Advanced NFL Stats Community comes in. If you'd like to publish your own research, you are free to do so at ANS Community. We haven't seen a submission since last season, and loyal editor Ed Anthony hasn't had much to do over the past few months. (I'm beginning to rethink his guaranteed salary of $6.5 million...no, wait. That's Matt Flynn, not Ed. I only pay Ed like $80,000/yr, but I'm not worried because it's in Canadian pesos or whatever they have up there. So that's what, $50 bucks or something in actual money, right?)
I know there's a lot of research out there waiting for the bright lights of ANS Community. I must have sent data to and answered questions for over (honestly) 100 students, from high school students to PhD candidates to tenured professors. And there are lots of armchair statisticians out there like myself, with their own ideas about football stats. Every post at the Community site has been read by thousands of readers, and the very best will find their way onto ANS proper.
I was going through the posts at the Community site and I was surprised to see there are 133 posts over the 5-year life of ANS-C, a substantial amount--an amazing 200 articles per year! (Or about that. I'm not good with numbers.)
Some of the posts were a bit out-there, but some of them are real diamonds. A few of my favorites were Bryan Davies' explanation of why a team should always go for two when down 14 and Michael Beuoy's team rankings based on multiple simultaneous equations of point spreads. (You can always check Michael's up-to-date rankings at his site Inpredictable.com.) Longtime reader Adam Tarr put together this examination of QB YAC, which broke the site's record for TL;DR flame-war comments. I liked this one by 'Tunesmith' on the Kelly Criterion, a financial market concept. And here's Ed's own (puzzling) contribution on kicking or receiving to start the half.
Here are Ed's favorite posts through the years:
ANS Partnership with Harvard Sports Analysis Collective
One of the new features this season will be a partnership with the Harvard Sports Analysis Collective. I've teased these guys in the past about their vaguely Maoist name, but I've always been a fan of their straightforward analytic style. Some of the brightest minds in analytics are coming from places like HSAC.
In case you're not familiar with them, HSAC is an undergraduate organization at Harvard College dedicated to the quantitative analysis of sports strategy and management. It was founded in 2006 under the guidance of Professor Carl Morris. HSAC's work has focused on applying some scientific rigor to sports analysis. Their previous work on the NFL has ranged from identifying inefficiencies in the NFL draft to criticizing poor in-game decision making, which you can find on their new website. Many of its members have worked in the sports analytics industry in both the media and on the team side. According to Kevin Meers, co-president of the group, says that right now they're focused on getting our bench press reps up so they can get off the computers and onto the field. Good luck with that.
Kevin will be coordinating weekly contributions from HSAC members here at ANS. He's majoring in economics with a minor in statistics. His work has focused on the NFL draft, but he is currently studying applications of game theory on in-game decisions. He has also spent the past two years as an intern in the NFL, and he may have been the only person from Washington DC who wasn't excited about the RG III trade.
Please welcome Kevin and HSAC, comrades! Look for their first post shortly.
Welcome to Our New Contributors!
First up is Dave Collins, who will be hosting the Advanced NFL Stats podcast. This will be a fun new feature that I'm really excited about. The podcast will come in weekly installments and will include a different guest from week to week. The first episode is already in the can and ready. Look for it shortly.
Dave hosts The Opening Play Podcast where he covers sports and comedy "in an intelligent way." His first summer job was as a tour guide for the Red Sox, and since then his love of sports, statistics and corny jokes about the Green Monstah has never waned. He graduated from Northwestern University with degrees in communications and economics and spent the 2009 football season interning with the Chicago Bears. Now in California, he works at StubHub.com and produces the Bay Area Sports and Tech Meetup . Dave can also be found performing improv comedy throughout San Francisco. Though he currently resides in the Bay Area, he remains a die-hard Patriots fan.
Next up is Sterling Xie. He's going to be doing the weekly write-up for the team efficiency rankings. Sterling is the type of devoted stats guy that makes former players and coaches roll their eyes while gushing spiel about the good ol' days. Sterling is currently enrolled in Hamilton College, working towards a degree in English. His work is featured on Bleacher Report and its partner websites, where he writes about all things Boston sports. He's a sucker for a good third-down back, and greatly misses rooting for Danny Woodhead.
Rob Hendryx will be handling the playoff projections this season. Rob is an engineering graduate student slave at the University of Texas at Austin. He has been researching sports statistics for a few years, mostly in the search of evidence that Tony Romo is not cursed. (Results are still inconclusive.) Recently he has posted his own research to reddit.com/r/NFLstatheads under the username kloverr, and moderated the small community there as well.
Andrew Carroll will be doing some general analysis. Andrew is a contributor at NinersNation.com and considers himself a 49ers/Chiefs fan. Less of a statistician and more of a wide-eyed, data wonking glutton, Carroll enjoys spreadsheets, numbers, stats, and otherwise-trivial data that provide a different perspective to the NFL landscape.
The new guys will join Jack and Keith who are returning for 2013.
Lastly, a very sincere thank you goes to all the guys who applied to be contributors at ANS this season. The response to the call for writers was overwhelming. This season I received three times as many submissions than I did for the last open call two years ago. I wish there was a way for everyone to have their football research read...which is why I created the ANS Community site. It never took off the way I envisioned, but it's still ready and waiting for interesting research and analysis.
Welcome Back, Football
Call for Writers: Update
Thanks to everyone who responded to the call for writers. Please be assured that all responses have been collected and will get a thorough look. I've combed through the spam filter so nothing gets lost. I'm over a week behind where I wanted to be in terms of reviewing them, but I'll get there. I intend to contact everyone over the next two weeks to finalize things.
Call for Writers 2013
This season Advanced NFL Stats is planning to add a small number of additional contributors. I’m looking for smart, articulate thinkers to bring a fresh perspective to the world of NFL analytics. Previous analysis or blogging experience is preferred, but not required.
Those interested should email me directly (see the About - Contact/FAQ menu link) no later than August 25th. Include the words 'Call for writers' in the subject line, please. Your email should include a brief introduction and links or attachments of two or more examples of your analysis and writing. If you have no previous experience, you can send ‘demo’ drafts of the kind of analysis you’d like to do.
In particular, I’m looking for contributors to ‘own’ a regular weekly assignment. For example:
Joint Statistical Meetings
Gagnez le jour, Alouettes!
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.