Game Changers: Bradford Goes Deep

The Situation
Cardinals at Rams, Week 5
Rams up 10-3, 11:58 left in the 4th Quarter
Rams ball, 3rd and 11 from the Rams 49

Washington Post: Where Does Robert Griffin III Stack Up So Far?

This week's article at the Post looks at what the numbers say about Griffin's hot start this season and how he compares to the rest of the rookie class.

Griffin is clearly moving the ball with both his arm and legs. He has generated just over 30 net EPA (net points) on pass plays and more than 13 net EPA on designed runs and scrambles. On a per play basis, his runs and scrambles are more potent, and by a large margin–about 50%.

The only statistical weakness Griffin’s numbers show is a high reliance on receiver yards after catch (YAC). Although his overall pass efficiency leads the league, he is 13th in “Air Yards” per attempt–passing yardage minus receiver YAC. Of the quarterbacks who have 100 attempts through week 4, Griffin has the third highest percentage of YAC. That’s not a bad thing in itself—more yards is always better...

Of course the comments at the Post quickly devolved into an argument about the presidential debate. I wonder what the WPA looked like for Obama last night. Yikes.

Week 5 Game Probabilities

Game probabilities for week 5 are up at the New York Times' Fifth Down.

This week I delve into Mark Sanchez's career stats. Why would the Jets give him a $20 million guaranteed extension?

Game Changers: Santonio Goes Down

The Situation
49ers at Jets, Week 4
Jets' ball, start of 4th quarter

Slate/Deadspin Roundtable: Why Do Coaches Punt? Here's Why

Here's a post I wrote up on the Carolina fourth down blunder from Sunday. Yes, of course they should have gone for it. This post is a little different--no math or WP calculations. This time I wrote about two psychological factors that conspire to make coaches punt-happy.

Here's the Slate link. Here's the Deadspin link. This post is a little more Slate's speed than Deadspin material.

The first fallacy is called base rate neglect. This is an error all people tend to make, even experts. The most common example is when doctors are asked to estimate the chances of someone having a disease given certain facts. They almost universally ignore the base rate of the disease—that, say, only one in 100,000 people in the population will ever contract it...

Similarly, when coaches are asked in postgame press conferences about fourth-down decisions, they discuss only the particulars of the situation: how successful they were on the two short-yardage plays earlier in the game, the nagging injury to the left guard, and the success his defense has had so far that day. What they always ignore is the base rate of success. But it's the most important piece of information. It's the one thing you'd want to know as a head coach in such a situation...

The Chiefs and Home Field Advantage at Arrowhead

I did a fun interview with Sean Keeler of Fox Sports Kansas City. He wanted to figure out what happened to the mystique of Arrowhead Stadium. What happened to the advantage the Chiefs used to have there? I think I came off as little too harsh on the Chiefs, and I've probably jinxed my hometown team this weekend.

Team Efficiency Rankings - Week 5

A lot of movement from week 3 to 4, as we'd expect. But actually, the median absolute (in either direction) movement was only 2 spots. The big movers were TEN, CIN, ARI, AND SEA.

How on earth did TEN move up 9 spots after a 38-14 divisional beatdown? Aside from turnovers, they played statistically well, especially on offense. Midway through the third quarter they were only down 7 with possession and a .31 WP, but a pick-6 quickly let the game get away. Turnovers are discounted by the model because they are so random. The biggest factor for TEN's climb up the rankings was opponent strength. HOU appears so dominant right now that just showing up on the field moves their opponent 5 spots.

CIN is climbing the ranks quickly because they put together a complete game against the Jags and their stomping at the hands of BAL is being averaged out by their performance since.

ARI is everyone's record-gazing outcome-focused darling of the moment. Their 4-0 record is deceiving, and I can already sense that they might be the post child for bad power rankings this season, like ATL was a couple years ago. First, they're 2 plays away from being 2-2. Second, their offense is terrible. They are tied for 28th in passing efficiency and dead last in run success rate.

Despite the apparently close score, SEA was soundly beaten by a very poor STL team. Russell Wilson posted just 0.2 adjusted net yards per attempt on Sunday. Laying an egg against the 23rd ranked team in week 4 will drop a team hard.

Typically, teams are bunched in the middle, so a relatively small change in their GWP can translate into a big movement in ranking. Also keep in mind that when a team's previous opponents move up or down, so does its own opponent adjustment. For example, the teams that have played CIN so far will get a bump in their rankings due to CIN's improvement. In other words, CIN is probably a better team than their previous stats had indicated. This early in the season, both of these factors can have a large effect.

With that, here are the efficiency rankings going into week 5. And as always, they are completely perfect and I personally agree completely with each and every ranking.

The inputs for the rankings are in the second table below, so if you have any questions why a team is ranked where it is, start there. Click on the table headers to sort.

Yes, that's right. The Saints are dead last.

Changes in the EP Curve over Time

I've written a lot about the continuing trend toward more potent offense and what it means strategically. But let’s look at things at a deeper level by examining trends in the overall NFL Expected Points (EP) curve.

As a refresher, EP is a concept of football utility. It measures the net point potential at any state of a drive, based on down, distance, and yard line. For example, a 1st and 10 at midfield represents 2 EP to the offense, meaning from that point forward it can expect, on average, a 2-point net advantage over its opponent. More details on the concept can be found here.

With offense gaining an ever firmer upper hand, the EP curve must be affected. But it can’t just be sliding up across all states. At its end-points, the curve must be bounded at slightly under 7 points at the opponent’s goal line to slightly less than -3 points inside a team’s own goal line. We would therefore expect the curve to bow slightly upward over time.

The graph below plots raw, unsmoothed EP values for 1st and 10 (or goal) states in normal football situations, when time is not yet a factor and the score is reasonably close. The blue line represents the first three seasons in my data set, 2000-03, and the red line represents the most recent three seasons, 2008-11.