Week 1 in review: Net yardage, Glicko, etc.

It’s not shocking that the Saints lost: they were playing a better team on the road. But it would have been a nice win to have, especially because the NFC South promises to be a competitive, if not stellar, division.

Here are the Glicko rankings after week 1 of the NFL season. I seeded the 2015 rankings with mean-regressed 2014 rankings. In other words, these rankings take last year’s ranking into account, at least a little bit. Don’t forget the rankings are dumb in that they only take a few things into account: wins, losses, consistency, and opponent strength. So if Aaron Rodgers (or, more pertinently, Jordy Nelson) got hurt last week, the Packers’ Glicko rating would not change until they started losing games.

In the chart, teams with green dots are above league average, teams with grey dots are around league average, and teams with red dots are below league average, at least according to the Glicko ratings. Also note that there’s a bug in the code I used to generate this chart, so the Bengals should be green and the Jets should be grey. Sigh.

Week 1 2015 Glicko ratings

Glicko has the Saints right at league-average, in the same ballpark as the Falcons and Panthers and notably better than the Bucs. Sounds about right.

Other graphs

I’ve been playing around with a few other graphs in an attempt to analyze last week’s game. They’re all variations on the theme of how to visualize possessions and field position within a game. I’m not sure how useful they are, but here goes.

This first one I’m calling a Net Yardage chart. It shows the cumulative net yardage for the Saints: a positive net yardage means the Saints have gained more yards than their opponents, a negative net yardage means they’ve been out-gained. These graphs count punts, punt returns, and penalties, but don’t count kickoffs and kickoff returns. Check it out:

Week 1 Net Yardage Chart

This chart shows that Arizona was fairly dominant in the first half: at no point did the Saints have more total yards than the Cardinals. That flipped quickly in the second half when Brees connected with Snead for a 63-yard gain. In all, the second half was much more even in terms of net yardage. The difference: the Cardinals scored touchdowns, the Saints scored field goals.

Here’s another chart I’ve been working on. I’m calling it a Ball Travel chart. It graphs the field position of the ball over time. Each individual line follows the ball as it moves across the field towards the Arizona end zone (marked 100 on the graph) or the New Orleans end zone (marked 0 on the graph). Once a team scores, the chart starts over. This might be more clever than it is informative, but I kind of like it. You’ll probably want to click to enlarge it:

Week 1 Ball Travel Chart

Finally, here’s one I’m calling a Drive Chart. It’s essentially the same as the Ball Travel Chart, but it displays each drive individually, color-coded by team. The dashed grey lines represent punts. Again, maybe more clever than useful, but I’m not sure.

Week 1 Drive Chart

I’m still working on automating these, so I probably won’t produce them every week. But it’s fun to screw around.

Exclusive Week 2 preview!

The Saints are, like, way better than the Bucs. They’d better win.


Updated Glicko chart

Here’s a Glicko chart for the 2014 NFL season. Tech details and optimizations still to come, but for this version I calculated 2013 Glicko ratings and used them as a starting point for the 2014 season. I also included error bars, which represent a 95% confidence interval for the rating. Essentially, if the bar from one team overlaps with the point from another team, then their ratings are statistically indistinguishable from each other. The dotted gray line is league-average. Check it out:

2014 NFL Glicko ratings

What I like about this is that it makes it easy to lump the league into three different categories: teams that are clearly above average (everyone from the Seahawks->Packers), teams that are about average (Chargers->Rams), and teams that are clearly below average (Vikings->Bucs). More in-depth analysis might help you distinguish the teams on a more fine-grain scale, but this rough cut is both a good start and a good reminder that we don’t know much after a 16-game season.

Once I get the final version refined (hopefully before the season starts), I’ll roll out a post explaining it in detail. Until then, consider this a work-in-progress.


Glicko Ratings for NFL Teams

I’ve been reading a bit about different rating systems (such as the ELO Ratings used by FiveThirtyEight) and came across an intriguing rating system developed by BU professor Mark Glickman. They’re called the Glicko Ratings. One nice thing about Glicko ratings is that they allow you to calculate deviations, which is a rough measure of uncertainty in the rating.

So I’m going to try to work with Glicko ratings a bit this year, updated weekly in the newsletter and then the site. More details to come (including some technical info), but for now, here is a first cut at the weekly Glicko ratings for the NFC South in 2014. Click to enlarge.

initial glicko ratings

There are many things wrong with this initial analysis. For example, they assume that all the teams are equally good going into the season, which isn’t exactly true. FiveThirtyEight solves this problem by using prior-season ratings (accounting for some regression toward the mean) as an input for week one. I’ll do that eventually, which should make the ratings a little better. There are other optimizations to make, too, in time.

That said, this first cut looks pretty good to me.


New web host

Hi there. I’ve updated the hosting on this site to something a bit cheaper but hopefully equally unreliable. You’ll notice there are no more ads (total haul over the lifetime of the site was about $10) and a new design.

There are likely some broken links and formatting, which I’ll try to fix over time. Thanks!

Here’s a test image, FYI:

Test Image


First issue of the newsletter is here

This week, I ask if Sean Payton is overrated and have two more thoughts! You can read the issue here and subscribe here or with the form below. Thanks!


Let's try something different

I keep thinking about what to do with this website. I don’t have the time or energy to do a podcast right now. The world doesn’t need a new football podcast at this point, anyway. I’ve posted a few random things this season, some more in-depth than others. But thanks to the main gig I can’t do in-depth analysis regularly enough to generate decent traffic. The result: people don’t think to visit this site, and I can’t blame them.

But I still love the Saints and think I have something to say. So I’m trying something new: an email newsletter. Really. It’s called Saints Thoughts, and it’ll be 3 (more or less) thoughts about the New Orleans Saints (more or less) sent to your email inbox every week (more or less). It’ll have a few graphs, a few stats, a couple of links…that kind of stuff. Relatively low volume and low commitment (on your part and mine). Plus it’s free. And no spam.

The first issue comes out next week. You can sign up [here][4] or fill out the form below. I hope that you do.

[4]: http://tinyletter.com/saintsthoughts


Division odds, week 11

Here are the division odds for week 11. The Saints are still favored to win the division, but it’s getting closer. And these odds don’t account for the loss of Brandin Cooks, which obviously makes things worse. Given the injury, and the relative ineffectiveness of the Saints’ receivers and tight ends this year, I expect Atlanta will probably win the division. Sigh. As usual, data from Football Outsiders.



and Pete the same

Just putting this here for Rog. No particular [reason][1]:

[1]: https://www.facebook.com/AdamSchefter/posts/854898527896123


NFC South Division Odds, week 10

The Saints are holding steady at around 77% this week, only down a bit after last week’s loss thanks to Carolina’s continued ineptitude. Atlanta’s, uh, rising up, though, so watch this space if the Saints can’t get it together. As usual, data from [http://www.footballoutsiders.com](Football Outsiders).


[1]: http://www.whodatreport.com/wp-content/uploads/2014/11/divisionOdds1.jpg


Division odds, week 9

Sorry this is a little later than normal this week. Real life intervened. As always, data from Football Outsiders.


[2]: http://www.whodatreport.com/wp-content/uploads/2014/11/divisionOdds.jpg