Playoff Appetizer: True Wins Plus (Fumble Adjusted)

We might be halfway through the first quarter of the first NFL playoff game of 2013, but I’m still finishing up with baseball and just getting warmed up on football. Football month on the blog officially kicks off today — there’s lots of interest stuff to come, from innovative rule ideas and play calling to new prediction methods and game analysis. Today, I’m trying an addition to the measure of NFL team quality that I debuted last year: True Wins. True Wins are calculated as follows:

True Win = Blowout Wins + Close Wins/2 + Close Losses/2 + Ties/2

You may recognize the intuition from pythagorean expectations — you get full credit for blowout wins (I define this as more than 7 points), but no extra credit for winning by huge margins, and you get half credit for all close games, since those probably come down to luck more than skill. Last year, I showed that True Wins predicts a little better than pythagoreans, and it’s a whole lot more direct. Both measures are much better than using wins alone, which unfairly penalize (reward) teams that lose (win) a lot of close games.

What Else is Luck-Driven? Fumble Recoveries?

With the playoffs coming right up, I decided to try an improvement that adjusts for possible luck in fumble recoveries as well. Here’s the logic (from Football Outsiders):

Stripping the ball is a skill. Holding onto the ball is a skill. Pouncing on the ball as it is bouncing all over the place is not a skill. There is no correlation whatsoever between the percentage of fumbles recovered by a team in one year and the percentage they recover in the next year. The odds of recovery are based solely on the type of play involved, not the teams or any of their players . . . Fumble recovery is a major reason why the general public overestimates or underestimates certain teams. Fumbles are huge, turning-point plays that dramatically impact wins and losses in the past, while fumble recovery percentage says absolutely nothing about a team’s chances of winning games in the future. With this in mind, Football Outsiders stats treat all fumbles as equal, penalizing them based on the likelihood of each type of fumble (run, pass, sack, etc.) being recovered by the defense.

The keys are:

1. Fumbles are huge turning points in games
2. Teams don’t maintain high or low recovery rates over time

To quantify #1, I determined the point value of a recovery. A simple regression of point differential in each game on total fumbles and fumbles

As the dust settles: week 17 recap and playoff preview

The playoffs are set! I’ll give my thoughts on each match up in a moment, but let’s look at what happened in week 17 first. Seven teams were fighting for their playoff lives, and 7 out of 9 that had clinched were still playing for a higher seed. Like last week, let’s start with the teams that have a legitimate chance to win the Super Bowl (at least 10 True Wins and a stable quarterback situation; if you haven’t read about True Wins yet, what are you waiting for?):

All these teams got the job done in week 17. I was confident that the Steelers would win a defensive struggle against the Browns

NFL week 17: contenders and pretenders

Week 16 was huge. Fifteen teams entered the week with work to do to make the playoffs (7 more had already clinched). Ten of those 15 teams played another team within the same group. That meant 5 guaranteed wins for these teams; only the Titans got a win outside of the group.

Before I break down the carnage, let’s look at the real contenders. Here are the True Wins standings for the six teams that I think have a chance (you can learn about True Wins in my previous post, which are my quick and dirty luck-free measure of team quality):

True Wins update heading into week 16

NFL playoff races heated up in week 15 (just like always). The Packers finally lost and the corks popped for the ’72 Dolphins (just like always), while all other NFC playoff teams held serve. The AFC was the mirror image. The Patriots are now cruising with the top seed (just like always) and a six game win streak, while all other AFC playoff teams lost but maintained their playoff positions. Yes, that’s correct, Tim Tebow lost.

Despite losses by the Broncos, Titans, Raiders, Bears, and Giants, no new teams were eliminated. The NFL must be thrilled! With two weeks to go, 22 out of 32 teams still have a shot for only 12 spots.

Before we see who actually deserves a shot,

Just a little bit of luck

A couple days ago, I showed that True Wins is an able replacement for Pythagorean wins as a simple, “luck-free” measure of team quality in the NFL. True Wins gives full credit for blowout wins and half credit for close wins and losses (defining close games as games within 7 points). Heading into week 15 tonight, I thought it would be fun to see how teams stack up this season. First, let’s look at teams almost certain to make the playoffs (4 of the 7 have already clinched):

True Wins agrees that the Packers are the clear best team, and there’s not much difference among the six teams at 10-3. All these teams have gotten a little lucky in close games (i.e., their wins are higher than their True Wins), but only the Packers and Saints True Win differences are especially high. These teams are all legitimate playoff contenders.

Next, consider teams still in the hunt (I’ll be generous and include 6-7 teams plus the Eagles):

Two point or not two point

This NFL season, Bill Barnwell is preaching quant analysis to the masses over at Grantland. My friend Chris linked me to his article yesterday, where he tackles a couple of topics: icing the kicker with a time out and going for a two point conversion. Coaches face these decisions a lot, so I appreciate the effort to tackle them rigorously. However, Chris and I found some flaws in Barnwell’s take.

Warmup: Icing the Kicker