Introducing Our New Writers

I'd like to introduce the new writers/analysts here at Advanced NFL Stats. I was surprised by the response to the call for writers, which was both a blessing and a curse. It was great because there are so many talented people with an interest in football stats, but it also meant making some tough choices on who to include. I leaned strongly toward people with previous analytic and writing experience. So without further ado, here is the new cast:

A Markov Model of Football

After an 11-yard sack, Donovan McNabb and the Philadelphia Eagles were backed up to their own 25 yardline. Down 17-14 to the Green Bay Packers with 1:12 remaining in the game, the top-seeded Eagles were on the verge of being eliminated from their first game in the 2003 playoffs. On 4th-and-26, the Eagles call for a 25-yard slant. McNabb drops back and throws a bullet to Freddie Mitchell in stride, converting and laughing in the face of probability. The Eagles then drove down the field and kicked a field goal, sending the game into overtime where they would eventually win. What are the odds that a drive containing a 4th-and-26 from the 25 would end with a successful field goal? According to the Markov model, a whopping 1 out of 175. 

Why Kick Deep From the 50?

A guest post from longtime reader Jeffery Clarke:

One of the effects of the rule change in starting kickoff positions is that it makes onside kicks a considerably better bet. When you add a 15-yard penalty to the equation, teams should consider making an onside kick a fairly standard play.

There have already been four kicks from the 50 yard line this year. None have been onside. Onside kicks need to go at least 10 yards, but historically they have averaged 13 yards. A regular kick from the 50 yard line will almost certainly result in a touchback. According to the WP model, drives that start at the 20 yard line are worth 0.34 expected points. From the kicking team's perspective, that is -0.34 points. If the kicking team fails to recover the onside kick, they can expect their opponent to start the drive at the 37 yard line. That would be worth -1.25 EP. If an onside kick was successful, the kicking team would start at their opponent's 37 yard line. That would be worth 2.84 points. A successful onside kick is worth 3.18 points more than the value of the touchback (2.84 minus -0.34). An unsuccessful onside kick is worth -0.91 points (-1.25 minus -0.34). Clearly, a team should attempt an onside kick if they think they have anywhere near a 50% chance at success.

Should The 49ers Have Taken Points Off The Board?

San Francisco fans are now questioning Jim Harbaugh's decision to defer enforcement of a penalty on a successful field goal that would have given his offense a first down deep in Dallas territory. Taking points off the board is often the smart play, so did Harbaugh make a good call?

On 4th and 1 with 11:16 in the 4th qtr, 49ers kicker David Akers booted a 55-yard FG to put his team up by 10. Cowboys linebacker Keith Brooking was flagged for a 'leverage' penalty, meaning he used teammates to help elevate himself attempting to block the kick.

As I understand the rule, Harbaugh had the option of accepting the penalty for a 1st down at the Dallas 22 or deferring enforcement to the ensuing kickoff. He chose to forgo the 1st down, take the 3 points, and take the 15 yards on the kickoff.

The Weekly League: Notes and Ideas for Week Two

Merely one of the jerseys Buffalo's Scott Chandler barely ever wore.

This week's edition of The Weekly League features

1. Previews for the Oakland-Buffalo, Green Bay-Carolina, and San Diego-New England games.

2. Some surprising facts about the Buffalo Bills and their Week One accomplishment.

and

3. Considerably more sass than frass.

Note: the author has replaced yards per run with success rate as the standard by which ORUN+ and DRUN+ are evaluated, on account of run success rate correlates with winning more strongly.

Oakland at Buffalo | Sunday, September 18 | 1:00pm ET
Four Factors


Notes
• Last week, the Buffalo Bills were the only team in the league to post above-average numbers in every one of the four factors (pass efficiency, pass efficiency allowed, run success rate, and defensive run success rate) en route to beating Kansas City, 41-7.
• Of course, one will note, a single game is a small sample.
• One will also note, however, that Kansas City was a better team than Buffalo last season and playing at home -- an advantage that would give one completely average team about a 57% chance of victory over another completely average team.
• Quarterback Ryan Fitzpatrick's relationship with tight end Scott Chandler proved particularly fruitful, as Chandler caught all five passes thrown to him, for an average of 12.6 yards per target (YPT) and 1.71 expected points added per play (EPA/P).
• This is the same Scott Chandler who had one reception in 14 career games entering the season.

Daniel Khaneman On 4th Down Decisions

Ok, not 4th down decisions exactly, but he hits the nail on the head here (via David Brooks):

People who have information about an individual case rarely feel the need to know the statistics of the class to which the case belongs.

Coaches want to know all about the particulars of certain situations: how fatigued the defense is, how the left guard has been playing today, how well the team has done in short yardage so far (sample size of 3 plays probably), how good the turf's traction is, and so on. But many coaches remain generally (and willfully) ignorant of the statistics of their larger situation.

Sure, all those little things matter, but not nearly as much as the 'class to which the case belongs', as Kahneman puts it.

Case in point.

Match Up Pages Are Back

One of the least well-known features on this site are the Match Up pages. They're a one-stop shop for comparing all the relevant stats between upcoming competitors. I created the pages originally as just a tool for myself, needing a quick and easy way to research the numbers for my posts at the NY Times and Washington Post.

There are tables to compare each team's conventional rate stats, offensive and defensive advanced stats, and offensive and defensive player stats. Unfortunately, it's quite an eye chart, so unless you're familiar with the stats and the tables, it might just seem like a wall of numbers.

You can get to them by clicking on the upcoming games in the scoreboard banner above, or you can always navigate to them directly at this address.

Washington Post: What Does Grossman's Good Start Mean?

Today's post at the Washington Post's Redskins Insider looks at Grossman's performance and its context in his career. I also grade the o-line, look at a 4th and 5 conversion attempt, and show that a 14-point margin of victory can be misleading.

Damn, I need to get a new picture to those guys. That's just awful.