The Broncos are still holding onto the top spot in the Advanced NFL Stats efficiency rankings this week, and they can thank Peyton Manning. Manning the Elder put together his most efficient game of the season Sunday night against the Saints, throwing for 305 yards and three touchdowns on 30 passes without an interception or a sack. His 10.2 adjusted yards per passing attempt was the best mark since Alex Smith carved up the Bills for 12.6 per attempt back in Week 5 (303 yards on 24 attempts).
Due to the bye, Manning is a bit behind some of his competitors in counting stats, but he has been elite this season by rate statistics. His 0.27 EPA per play is behind just Matt Ryan (0.29) and tied with Ben Roethlisberger for second in the league. His 7.0 AYPA gives him a runaway lead -- the difference between him and second place Tom Brady (6.5) is bigger than the difference between Brady and 9th place Carson Palmer.
But Manning has had utterly transcendent seasons before. How is his performance standing up to his Colts career? Let's look on a game-by-game level. Each orange bar represents a game with Denver, each blue bar a game with Indianapolis:
Is 2012 Peyton Manning's Best Season Since 2004?
Alex Smith: Counterexample
Sure, you might be able to point to a QB here or there who came on strong to become a consistently above-average player several years his starting career, but for every guy like that (Steve Young might be the most notable) I'll give you multiple Joey Harringtons, Kyle Bollers, Rex Grossmans, and David Carrs.
Alex Smith would have been on that list too, at least until the last couple seasons. He might be the exception to the rule. After Smith's phenomenal game Monday night in which he went 18 for 19 with three TDs, I wondered what really made the difference. A lot of credit has been given to second-year head coach Jim Harbaugh and a new offensive scheme. It's hard to argue otherwise, but I will anyway. Looking at his career trends, he began a significant and consistent improving trend immediately following his missed season of 2008. His improvement from 2009 to 2010 in terms of WPA, EPA, SR, and AYPA under Singletary was as big as his improvement in 2011 after Harbaugh took over. It's as if Smith has had two different careers, a brief, erratic, injury-plagued three-year span from 2005 to 2007, and a middling but improving span since 2009.
Team Efficiency Rankings - Week 9
ATL finally moves into the top tier of efficiency to match their undefeated record. The biggest curiosity to me has to be CAR, ranked 6th despite being 1-6. I can see why they're ranked 6th in terms of efficiency--their offensive pass efficiency is 5th in the league, their defense has been a little better than average, and they've had a relatively tough schedule so far. They've been undoing themselves with critical turnovers and have come up short on very high leverage situations. I doubt seriously they are the 6th best team in the league, but they are probably much better than their record currently indicates.
Here are the full efficiency rankings for week 9. Click on the table headers to sort.
Risk-Seeking Behavior?
Mike makes risk-seeking pretty clear with an example: "You'd think a person would pay $1 for a 1% chance to win $100. But they don't. They're willing to pay $5.50! For a 10% chance of winning $100, they're willing to pay $18.60."
I've been looking for examples of risk-seeking behavior in the NFL for years, and although there are a few examples of coaches going for it on 4th down when they probably should kick or punt, these examples are extremely rare. In fact, coaches are so reliably risk-averse on 4th down, I use such counter-examples to identify bugs in the algorithm or errors in the NFL's data.
So I thought I'd throw it out to the smartest readership in football--you guys. Are there any examples of consistent risk-seeking behavior in football? What about in all of sports--soccer, cricket, rugby?...I know there are some diverse fans out there.
What about in finance?
First Falcons Drive & Botched Bears Field Goal
Andy Reid had never lost coming off a bye week in his head-coaching career. Matt Ryan did not care. Leading the Falcons on a 8 minute 44 second opening drive, Ryan and company marched 80 yards down the field over 18 plays before hitting Drew Davis on a 15-yard touchdown. Up 7-0, the Falcons were 72% favorites to win the game and that probability would never dip below that the rest of the day.
Here is a quick look at Matty Ice's first drive -- on which he went 6 for 7 for 62 yards -- using our Markov model:
The Field Goal Likelihood Nexus
In this case I was looking at the probability of ending a drive with a made field goal in 2nd and 3rd down situations. (Second and third down modeling is especially challenging because there are fewer cases of each successive down. Plus there is an entire other dimension to consider--to-go distance. By comparison, first downs are almost always 10 yards to go.) After seeing the plots I thought there was clearly something wrong.
You'd expect that having fewer yards to go would lead to scoring more often, but once you think about it that's not always true when looking at only field goals. For most of the field, having fewer yards to go is better, but once a team passes a certain point, having more yards to go means it's more likely that a drive will stall inside field goal range.
Sunday's Numbers Have Been Crunched
2012 Is the Year of the Comeback, So Far
I did some analysis for Judy Battista's recent New York Times article about the flurry of big comebacks this season. Don't overlook the article's graphic link to see some cool details.
Big, unlikely comebacks, in which teams overcame chances of winning of no better than 1 in 10, have occurred about twice as often so far this season as they did in the previous dozen seasons...Twenty percent of the games in the first seven weeks of the 2012 season had a comeback factor of 10 or more, meaning a team overcame at least a 1-in-10 chance of winning at some point in the game; only 11 percent of the games from 2000 to 2011 featured such turnarounds. Ten percent of the games this season had a comeback factor of 20 or more, meaning a team overcame at least a 1-in-20 chance of winning, but only 5 percent did so from 2000 to 2011.
You can find the biggest comebacks for any team or season using this tool.
Matt Stafford Exposed As Bears Shut Calvin Johnson Down
The Bears defense has been a force all year. It's latest accomplishment: shut down Calvin Johnson. Despite Matt Stafford's efforts to find his star receiver, the Bears didn't let it happen. Stafford threw in Johnson's direction 12 times but only completed three for 34 yards and no scores.
With Johnson out of the picture, the Lions' passing game was impotent until a largely meaningless last-minute touchdown drive to pull the score to 13-7. Prior to that final drive (5-for-6, 67 yards and a touchdown), Stafford was 23-for-40 with just 197 yards an an interception to go with two sacks for -5 yards. The result: a horrid 3.7 adjusted yards per passing attempt.
It was just another disappointing game for Stafford in his fourth season as Lions quarterback. The former number one pick has fallen out of the top 10 in EPA per play (down from 0.19 to 0.14) and adjusted yards per passing attempt this season (5.9 to 5.1).
Despite Stafford's overall ineffectiveness, Johnson has still made a massive impact by EPA -- his 42.4 mark leads the league as does his tremendous 0.60 per play -- but his yards per target has dropped from 10.9 to 8.8 and he has just one touchdown through six games after 18 in 17 last year.
One thing hasn't changed: Stafford is still targeting Johnson on just under 25 percent of his passes, a plurality, and the reasoning is clear: the Stafford-to-Johnson connection was leaps and bounds better than any other passing weapon the Lions could offer. As expected, given Johnson's tremendous ability, the Lions exhibited one of the biggest drop-offs between top wide receiver production and production from the rest of the corps in 2011:
The above chart shows overall yards per attempt against yards per attempt when targeting all receivers except their top target. To ensure all receiver targets (or at least a vast majority) were coming from the same quarterback, I limited it to quarterbacks to play all 16 games. Stafford's drop-off when going away from his top receiver is one of the biggest -- nearly a full yard per attempt, right with Eli Manning and Cam Newton.
Washington Post: How Griffin Can Continue to Run and Stay Healthy
This week's article at the Post breaks down how Robert Griffin III can continue to take advantage of his running ability and stay off injured reserve.
Griffin’s scrambles tend to be more productive than his designed runs, but they also have another benefit which may be considerably more important in the long run. On his scrambles, Griffin made it out of bounds 17 of 20 times. On designed runs he got there just 8 of 38 times. Although getting out of bounds is certainly no assurance of evading a bone-crushing tackle, it does tend to spare a runner the kind of hit that puts a player on injured reserve. Plus, there is a reduced chance of fumbling and losing a fumble near the sideline.
Weekly Game Probabilities
Game probabilities for week 8 are up at the New York Times' Fifth Down.
This week I look at the annual game in London and try to figure out why the Rams might be favored over the Patriots.
Efficiency Rankings - Week 8
No intro this week. Just numbers.
Sunday's Numbers Have Been Crunched
A Week of Weak Decisions
There were a plethora of interesting coaching decisions this week, especially in the early games on Sunday. Avid readers cringe at these conservative calls so let's look at a few of them a little closer.
Cleveland Browns: Punted on 4th-and-1 on the Indy 41-yard line down by four with a little over six minutes remaining.
On what was likely the worst decision of the day, the Browns cut their expected win probability almost in half by punting. On 4th-and-1 from the opponent's 41, you should almost always go for it. You are expected to score +1.58 points by going for it (74% league-wide conversion rate) versus -0.04 points by punting.
Podcast with Carson
I just listened to some of it--apologies for all the ums and ahs and you knows. Very tired this week.
Ray Lewis - Dominant Playmaker of His Era
Ray Lewis is the kind of player you absolutely need to watch with your own eyes to appreciate Stats, advanced or otherwise, do him no justice. If you ever get the opportunity, watch the replays of the 2000 season's Super Bowl or any game from that year. Ray Lewis was super-humanly fast and powerful.
As a fan who'd watched more than his share of football, I was trained to expect patterns. Here's the same old hand off up the middle, RB sees a hole, cuts, 5 yard gain. Pitch to the outside, RB tries to turn the corner, squeezes around the DE, turns up field, might break off a big run if he can shake a tackler. Play action, 10-yd pass to the TE over the middle. Let's face it. A really big chunk of NFL football is predictably boring.
But watching Lewis at his peak confuses the brain. The rules and patterns of typical NFL plays that we expect to see were broken. Instead of RB sees a hole, cuts, 5 yard gain--it's RB sees a hole, cuts, 5-yd...OH MY EVERLIVING GOD! WHAT THE F?!! JESUS HAVE MERCY. WHAT WAS THAT?!!! Ray Lewis just penetrated from the back side of the play and dragged down the RB from behind for a 2-yd loss.
You know those video games like Madden football that usually have some sort of 'cheat code' that allows players to dial in invincibility or supernatural speed and strength attributes to their game characters? At his peak, Lewis was just like that. Lewis had the cheat code of reality in his DNA.
Although numbers aren't required, that's never stopped us before. So here are +EPA numbers for the top producing LBs of the NFL digital era. (Data begins in 2000). Except for the column on the far right, all numbers are per game averages. The right-most column is the player's grand total for the era.
Although this doesn't show us career numbers before 2000, they still show how dominant and consistent Lewis was among his peers. Even well into his mid-thirties, he was among the very top play-makers.
Weekly Game Probabilities
Game probabilities for week 7 are up at the New York Times' Fifth Down.
This week I look at the the showdown between the AFC leading Ravens and Texans.
Washington Post: All About Home Field Advantage
Following a Redskins win that broke an eight-game home losing streak, this week's article at the Post looks at home field advantage and its causes.
Home advantage is universal in sports. Whether it’s a team or individual sport, professional or amateur, virtually all athletic competitions have a home advantage. Fans like to believe they are the cause. Communication is essential in football, audibles and snap counts being the most obvious. The players themselves tell us it makes a difference. As plausible as this explanation may seem, the evidence suggests home advantage does not come from the crowd.
Game Changers: Dez Drops the Ball
Dallas at Baltimore, Week 6
4th Q
Ravens lead 31-29
Dallas ball; 2 point conversion attempt
Anatomy of a Comeback: Denver Takes Down San Diego
With 5:02 left in the third quarter Monday night, Philip Rivers threw incomplete to Dante Rosario on second and eight. Maybe this drive would stall, but the Chargers held a 24-7 lead and the time to pull together a comeback appeared to be running out on the Broncos. Denver held just a 0.03 win probability, after all.
Of course, on the next play Elvis Dumervil strip-sacked Rivers, Tony Carter picked up the loose ball and 32 yards later and an extra point later it was 24-7 Chargers. Seemingly just as soon it was 24-14, and 24-21, and 28-24, and 35-24. And then game over. How did the Broncos, so utterly dominated in the games first 40 minutes, come back to take home the victory (and with it, the top spot in our efficiency ratings)?
Game Changers: Rivers Nails His Own Coffin
Broncos at Chargers, Week 6
3rd Q, 11:29 to go
Chargers lead 24-21
Chargers ball; 3rd and 8 from their own 31
Win Probability, In Color!
Nothing new here. I just thought this looked cool. It's the win probability of an offense with a first down trailing by 3 points. Actually, it is a little new. I'm trying to get smart on multivariate non-parametric kernel smoothing algorithms using R, the open source statistics package. That's just a fancy way of filtering out the noise inherent in the raw data and making a smooth estimate of the true probabilities. This chart is a product of my experimentation.
This axis going from 5-95 represent the midpoint of 10-yard bins of field position. The axis labeled 0-50 represent the game time remaining. The z-axis (vertical) shows the expected win probability. It's a little over-smoothed, at least in terms of field position. It might be under-smoothed in terms of time. Still have a lot learn.
Team Efficiency Rankings - Week 7
The one thing the popped out at me was BAL falling to 17th. Everyone else has them as a top 5 team. At 5-1, their record certainly makes them look that way, tied for best in the AFC. But they are 3 simple game-deciding plays from being 2-4 and another 3 points from being 1-5: Tucker's squeaker of a FG vs NE, DAL's missed FG last week, and an incomplete Weeden pass into the endzone. Plus, they barely survived KC, winning 9-6 in a game in which they were mostly outplayed. Even before their recent injuries on defense, I think they've been generally overrated.
ATL is another curiosity. Despite having the best record in the NFL, they are 10th here. They have an average passing attack and they can't run the ball. Plus they have an average pass defense except for a very high interception rate which is bound the regress sharply.
NYG and GB are the top up-movers this week, thanks to beat-downs of top-ranked opponents on Sunday.
Here are your rankings for week 7. Click on the table headers to sort. The efficiency stats that comprise the inputs of the model are shown below.
Running to Create a 'Manageable' 3rd Down Is Self-Defeating
One of the common defenses of a run-heavy offense is that offenses need to make their third downs “manageable,” meaning short enough so that conversion is easier. The thinking goes that if an offense runs on either or both first and second down, it is relatively assured of shorter rather than longer distances on third down. At first look, this makes a lot of sense. After all, who wants to face third and long?
There are two problems with this argument. The first is that football is not a game of piling up first downs. The days of inching toward the goal line on 18-play drives are long gone if they ever existed at all. Football is, for the most part, a game of maximizing score differential, and the concept of Expected Points shows that NFL offenses are generally running too often on first and second down.
The second problem is that even if gaining a first down is the primary objective, running on first down is becoming a worse idea every year. The graph below shows that passing on first down leads to a conversion more often than running on first down. As usual, I limited the data to plays in ‘normal’ football situations, when the score is relatively close and time is not yet a factor at the end of either half.
Sunday's Numbers Have Been Crunched
Cardinals Don't Believe Closer is Better
With three minutes left in the game, the Cardinals got the ball on their own 15-yard line, down 16-13 to the Bills. John Skelton, in for the injured Kevin Kolb after the fourth play of the drive, leads the offense to the Buffalo 43-yard line where they stall on three straight incomplete passes. So, it's 4th-and-10 with 1:14 remaining, do you attempt the 61-yard field goal for the tie, or try to convert the 4th-and-long?
Groupthink in the NFL says attempt the field goal, but as those avid readers will certainly know, groupthink is often far too conservative. Here is the breakdown, via Brian's 4th-down calculator:
At ANS Community
Longtime reader Jim Glass puts some famous streaks in perspective--those of Unitas, Brees, and DiMaggio. Good stuff.
This is a good opportunity to remind everyone about Advanced NFL Stats Community, edited by Ed Anthony. ANS Community is a platform to publish your own football research. I know you're out there because I get questions and requests for help and data almost daily from graduate students and amateur stat heads. If you've written a paper for a class or have made your own ranking/prediction model, ANS Community is a great way to get it seen by thousands of smart readers. If you've been taking advantage of the play-by-play data we provide, we'd love to see what you've done at ANS Community.
Submissions can be sent directly to Ed at this address.
Weekly Game Probabilites
Game probabilities for week 6 are up at the New York Times' Fifth Down.
This week I dig into the Steelers' uncharacteristic numbers this season.
Washington Post: 'Manageable Third Downs'
This week's article at the Post looks at how third down conversion rates can mislead coaches into poor strategic approaches.
Offenses are better off thinking of their three downs (and fourth when the situation requires) as isolated opportunities for ten-yard conversions rather than stepping stones toward what coaches call a “manageable third down.” The best third down situation isn’t third and 1 or even third and inches. It’s converting on first or second down, before ever reaching third down. Rather than seeking a short third down situation, offenses should be avoiding third downs whenever possible.
J.J. Watt Continues Ascension As League's Best Defensive Player Against Jets
J.J. Watt shaped another game with his big mitts Monday night. The Jets put together a valiant effort in East Rutherford, falling just 23-17. Sure, it took a touchdown drive coming off a Matt Schaub interception and a 100 yard Joe McKnight kickoff return, but moral victories are moral victories.
And it could have been a real victory if not for Watt. His involvement was constant once again, as Watt was at least a part of eight successful plays for the Texans defense -- tied for the week high and a whopping 14% of the 57 plays the Jets ran in total.
Watt ran away with the week high in +WPA with 0.57, a result of his pervasive dominance to be sure but mostly coming from one swing play at the end of the first half, a tipped Mark Sanchez pass deflected right into the waiting hands of Texans cornerback Brice McCain. The Jets were 12 yards away from a tying touchdown; instead, McCain's 86-yard return set up a Texans field goal for a 10-point halftime lead.
That play alone generated 9.37 expected points for Houston and gave them a huge +30% win probability. It is the definition of a gamechanger. And this type of performance from Watt is nothing new:
Watt's three pass deflections Monday night made him the 38th defensive lineman since 2000 (as far back as we have the data) to record at least eight in a season. His season is five games old. According to our data, Richard Seymour owns the record with 12 deflections for New England in 2003. Watt has 11 games to knock down five more passes.
And this is just one part of his wide-ranging defensive game. It brings a depth rarely seen at the position and has turned Watt into by far the most productive defensive player in the league this season. He is running away with the +EPA lead -- 49.7 to Tim Jennings's 32.7. He's making plays that add up to nearly a touchdown and a field goal every week. He's a huge part of why the Texans are the second-best team in our efficiency ratings, and at this rate, Watt just may be en route to the biggest season by a defensive player we will ever see.
Team Efficiency Ratings - Week 6
Game Changers: Browner Reads the Option
Seahawks at Panthers, Week 5
3rd Quarter, 2:46 left to go
Panthers ball, 1st and 10 from their own 30
New Site Feature: Permanent Air Yards Page
Reid's "Gutsy" Call Goes Unnoticed
Down six to the Steelers on the road, Michael Vick and the Eagles took the field near the start of the fourth quarter. After three short gains, the Eagles faced a 4th-and-1 from their own 30-yard line. In today's NFL, this is an easy decision for coaches: Teams punt the ball over 90% of the time. Since there was still significant time remaining in a one score game, it's safe to assume that the Eagles should have performed similarly to a score and time-agnostic situation (although obviously it had some factor in Reid's decision).
Reid was feeling some extra confidence from his tufty moustache, so he decided to go for it. I mentioned it was an easy decision for coaches to punt, but is it the right decision?
Sunday's Numbers Have Been Crunched
Marvin Lewis Kicks Down by 4 with 3 Minutes to Play
Jason Lisk uses the Fourthdownulator to analyze Marvin Lewis' curious decision to kick down by 4 with 3 minutes to play:
Marvin Lewis cost his team dearly. About 13.5% chance of winning. That may not sound like a lot to you, but it’s huge. He almost cut it in half. You may be shocked to see that the chances of winning weren't that much better being down by 1-2 instead of 4-5, but that’s because coaches are conservative and play for field goals. When they need touchdowns, they act more optimally. Well, unless they have three minutes left.
Punting From Your Own Goal Line
Recently, we looked at how teams are too conservative with play calling when backed up against their own end zone. The main idea is that coaches want to give their team more room, and in particular, they want to give their punter more room so he does not have to stand in the back of the end zone. But, are punters actually more efficient with more room between them an the end line?
Let's look at average EPA on punts based on yards from goal. Specifically, we're going to look at inside the 3-yard line vs outside:
2012 Play-by-Play Data Posted
Play-by-play data through week 4 of the 2012 season is now available. I think this project deserves a cool name like baseball's Retrosheet. It doesn't go back to 1801 or whenever Retrosheet starts, but it's something. Suggestions welcome.
Happy crunching.
Observations: Thursdays' Rams-Cardinals Game
St. Louis
- Janoris Jenkins looked like a very capable corner, and given a year to get used to the NFL game, he could be an absolute stud. Combine Jenkins with Cortland Finnegan and the rush from Chris Long and Robert Quinn, and it's going to be very hard to pass against the Rams.
Game Changers: Bradford Goes Deep
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
49ers at Jets, Week 4
Jets' ball, start of 4th quarter
Slate/Deadspin Roundtable: Why Do Coaches Punt? Here's Why
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
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
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.