Roundup 10/30/10

Football match-ups are intransitive. Team A beats team B, who beats team C. So we'd expect team A to beat team C, right? Not always. So far this year there have been 11 such cases of 3-team intransitivity.

"Second team" All-Pros from the AP are selected the wrong way.

How many Super Bowl-winning QBs are playing in the league in any given season?

Mitchel Lichtman on luck in baseball, but it applies to sports in general. It applies to the whole world, for that matter.

For those who missed it, Andy Steiner takes a look at 'momentum' following interceptions at the Community Site. Awesome.

The Weekly League: Notes and Ideas for Week Eight

This week's edition of The Weekly League features:

1. More bullets than a John Woo film.
2. The words "Randy Moss" six times, including this one.

and

3. The GWP Record and Luck table that is sweeping the nation.

The Four Factors you see for each game represent each team's raw performance thus far in four important categories (pass and rush efficiency, pass and rush efficiency against) relative to league average (where 100 is league average and anything above is good).

Along with the Four Factors, you'll see two other numbers: Generic Win Probability (GWP) and Game Probability (PROB). The GWP is the probability a team would beat the league average team at a neutral site. It can be found for all teams here. The PROB is each respective team's chance of winning this particular contest. Your host, Brian Burke, provides PROBs to the New York Times each week, and those numbers (along with methodology) can be found here.

The following games have been chosen as they'll be available to the greatest portion of the network-watching audience, per the NFL maps at the506.com.

Finally, a glossary of all unfamiliar terms can be found here.

It's an adventure, America, and we're on it together!

Denver vs San Francisco (in London) | Sunday, October 31 | 1:00pm ET
Four Factors


Notes
• At 53 percentage points, the Broncos feature the largest split between pass and run efficiency relative to league average.
• Arizona and Buffalo are next -- at 38 and 37, respectively -- but both have considerably stronger running than passing games.
• Troy Smith will start at quarterback for the Niners, in place of Alex Smith, who suffered a left shoulder sprain last week.
• The former actually performed decently in 2007 with Baltimore, producing a 5.3 AYPA -- versus Kyle Boller's 3.8 and Steve McNair's 3.9. (League average that year was about 5.5.)
• Not that Boller and McNair were, you know, all-pros.

Raheem Morris Says Stats Are for Losers

Raheem Morris, head coach of the 4-2 Buccaneers, says that "Stats are for losers." Well, Raheem, I have just one thing to say to you.

I agree.

Most football stats are pointless. Total yards, field goal percentage, fantasy stats, total tackles, and the king of all bad stats--passer rating--are not much more than trivia. Coach Morris prefers to focus on wins, saying, "...you keep looking at stats and we'll keep looking at wins." Here, we are in complete agreement.

At the time Morris made the comment, he was confronted by a reporter with his team's standings in terms of total yardage gained and allowed. Those statistics can be very misleading and are often disconnected with winning. How do I know that? From other, better statistics.

NYT: Game Probabilities - Week 8

Weekly game probabilities are available now at the nytimes.com Fifth Down. This week I also look at how the Cowboys' downgrade at quarterback might affect their chances against Jacksonville.

Washington Post: Can One Player Single-Handedly Win a Game?

Today I've got another post up at the Washington Post's Redskins Insider site. This time I look at DeAngelo Hall's single-handed performance last Sunday against the Bears. Some other Redskins nuggets include:


-Just how hard did the Redskins offense try to lose Sunday's game?
-Lovie Smith's big replay blunder
-Albert Haynesworth's impact
-Former Redskins making waves in the league
-Why the Redskins have played in so many close games this season
-How badly the loss of Tony Romo hurts Dallas

Interceptions and Counter-Momentum

Over at the Community Site, contributor Andy Steiner has a very intriguing post. I normally link to the community posts in my weekly roundup, but this one was so interesting it merited some extra attention. Andy looks at whether teams tend to score more points following an interception than when they get the ball by other means.

I'd like to know what everyone thinks. I've been meaning to do a grand study of momentum, but haven't set aside the time to do it justice. Any suggestions on how to structure further research, using EP or WP perhaps, are appreciated.

Thanks, Andy.

Efficiency Rankings - Week 8

With the exception of San Diego still up at number 2 this week, the rankings are starting to make sense. Or, is it that perception is catching up with the stats? There were some big movers this week, including Tennessee, New England, Dallas, Atlanta, and Chicago.

The team rankings below are in terms of generic win probability. The GWP is the probability a team would beat the league average team at a neutral site. Each team's opponent's average GWP is also listed, which can be considered to-date strength of schedule, and all ratings include adjustments for opponent strength.

Offensive rank (ORANK) is offensive generic win probability, which is based on each team's offensive efficiency stats only. In other words, it's the team's GWP assuming it had a league-average defense. DRANK is is a team's generic win probability rank assuming it had a league-average offense.

Lovie's Latest Blunder

I already have a post this season called Lovie's Blunder, but I guess I'm just not terribly imaginative, much like many coaches in the NFL.

In a tight game against the Redskins, Smith decided not to challenge Jay Cutler’s fumble on first and goal from the one. Most accounts claim the replay clearly showed the ball crossed the plane of the end zone prior to the fumble. Had the play been a touchdown, the Bears would have been up 11 points early in the third quarter, giving them an 89% chance of winning. Instead, the fumble put the Bears’ chances at 70%, a difference of 19%. To put that in perspective, only two of the game's plays were more significant, and they were the two interception returns for touchdowns.

Smith had lost a challenge on the prior play, and you have to think that must have affected his judgment.

Just for the sake of argument, let's assume that the Bears eventually found themselves down by 3 points inside the two-minute warning. (They were up by 4 at the time of the play.) If we value a timeout as a full 40 seconds between plays, the difference in Win Probability (WP) between having 2:00 left to play and 1:20 left to play at their 30 yard line would have been 0.04 WP (0.24 WP compared to 0.20 WP). The difference between having 60 and 20 seconds to play is 0.07 WP. The biggest difference in the value of a timeout is between 40 seconds and zero seconds (a certain loss), which is 0.10 WP. Assuming the challenge had a reasonable probability of being upheld, he should have thrown the flag.

How Poorly Is Brett Favre Playing This Season?

Last season was magical for Brett Favre, as everything seemed to go his way. In the 2009 regular season, Favre accumulated +3.08 WPA, good for fifth in the league. That's an average of +0.19 WPA per game, meaning his performance would take an average team from a 50/50 team to almost a 70/30 team. That's impressive for an athlete of any age.

This season is different. Injuries and distractions appear to have taken their toll. Through week 7, Favre ranks a very distant last in total WPA, with -1.89, nearly three times worse than the next worst passer. That's -0.32 WPA per game. He's behind Trent Edwards, Jay Cutler, Matt Moore, Jimmy Clausen, Max Hall--everyone.

It's not just bad timing or bad luck in high leverage situations, either. Over his six games, he's responsible for -20 EPA, which is basically net point (dis)advantage. He's 5th worst in Success Rate (SR) among qualified QBs, meaning he's consistently bad, and not just a victim of a handful of high impact plays.

What about the Steelers? Should They Have Gone for the TD?

The Steelers were trailing the Dolphins by 2 points with 2:28 to play. After a very controversial replay, which I won't get into here, the Steelers faced 4th and goal from inside the 1. They elected to kick a FG, and hung on to win 23-22. But should they have gone for the TD?

FGs from that range are virtually automatic. But with that much time left, a FG gives the Dolphins plenty of time to get into FG range in response. With a FG and a 1 point lead, PIT would have a 0.59 WP.

Going for it from the one on the goal line would typically be successful 68% of the time. A TD and a 6 point lead would make MIA's task that much tougher, giving PIT a 0.74 WP. A failed attempt would give MIA the ball inside their own 1, worth about 0.19 WP for PIT. I say 'about' because there are few examples of teams backed up on their own goal lines with a 1-point lead.

Should NE Have Gone For It on 4th and 1?

Ahead by 3 with 2 minutes left to play, NE faced a 4th and 1 from their own 49. In a move reminiscent of the infamous 4th and 2 call against the Colts last season, Bill Belichick went for the conversion. RB Ben Jarvis Green-Ellis was dropped two yards shy of the line of scrimmage, turning the ball over on downs to a rallying Chargers team. Was it a good call?

From midfield, punts tend to net 35 yards, giving the Chargers possession at their 16. With just under 2 minutes to go and all 3 timeouts, SD would have a 0.15 WP.

A successful conversion for NE wouldn't seal the win. Because SD still had 3 timeouts, they'd need one more first down. Since it's uncommon that the trailing team would have all 3 timeouts, to estimate NE's win probability properly, we'll dig one level deeper. Teams up by 3 near midfield with 2 minutes to play convert 1st downs 45% of the time. So a successful 4th down conversion seals the game 45% of the time, and it leaves SD with the ball near their own 15 with no timeouts 55% of the time, worth 0.12 WP. This essentially gives SD a 24% chance to get the FG, and then a 50/50 shot in OT. A successful conversion would be worth (to San Diego):

The Weekly League: Notes and Ideas for Week Seven

This week's edition of The Weekly League features

1. Yet another in a series of paeans to the San Diego Chargers.
2. Some very brief, largely unhelpful notes about three NFL games.

and

3. The courage of a lion.

The Four Factors you see for each game represent each team's raw performance thus far in four important categories (pass and rush efficiency, pass and rush efficiency against) relative to league average (where 100 is league average and anything above is good).

Along with the Four Factors, you'll see two other numbers: Generic Win Probability (GWP) and Game Probability (PROB). The GWP is the probability a team would beat the league average team at a neutral site. It can be found for all teams here. The PROB is each respective team's chance of winning this particular contest. Your host, Brian Burke, provides PROBs to the New York Times each week, and those numbers (along with methodology) can be found here.

Finally, a glossary of all unfamiliar terms can be found here.

New England at Dan Diego | Sunday, October 24 | 4:15pm ET
Four Factors

GOTW
For the footballing enthusiast, this is really the game of the week. For two reasons. For one, it'll be broadcast on network television into nearly every home east of the Mississippi (and many west of it, too). For two, it features a Charger team that is quickly becoming a riddle wrapped in a mystery inside of a -- well, you know.

Roundup 9/23/10

Keyshawn Johnson thinks Romo is average, and he's holding the Cowboys back. Jason Lisk would beg to differ. This year, Romo sports a +30 EPA, meaning his play would be expected to generate 30 points of net point advantage over five games. But he has a negative WPA, meaning he hasn't played well in high-leverage situations.

Jason has been writing at a site called The Big Lead, which, except for JKL's stuff, is mostly pedestrian. The good news is that you can subscribe to Jason's stuff only using this feed link. Here's another neat post in which Jason looks how a few teams compare to historical teams with similar statistical profiles.

Say it ain't so, Phil!

More Phil on how mainstream reporters should report on sabermetric research. I've always had a very good experience working with reporters. They've been open-minded, inquisitive, and willing to accept that sometimes there's no statistical weight to the argument they're trying to make.

How amazing are the 2010 Chargers?

This seems to be a good idea.

Detecting momentum is harder than you think. I've been thinking of various ways to construct a research test for momentum in football games for a while. I have a few thoughts, but more ideas are always welcome.

WR Expected Catch Rate

One of the neat features on the individual stat pages are some receiver stats you don't typically see. There's targets, target percentage, yards per target, catch rate, and deep percentage. Occasionally you'll find target stats on conventional stat sites, but I think target percentage is more interesting--the percentage of team targets each receiver gets.

The other day I was sorting the WR stats page by Catch Rate (CR), which is simply receptions per target. I wanted to see which guys had the better hands. To no surprise, catch rate is closely related to how often a receiver is thrown deep balls. Deep% is the proportion of targets thrown in the air deeper than 15 yds past the line of scrimmage. The relationship between CR and Deep% for receivers with at least 40 targets in 2009 is plotted below. The relationship in 2010 shows virtually the same pattern, but is slightly more scattered because of the smaller sample.

NYT: Game Probabilities - Week 7

Weekly game probabilities are available now at the nytimes.com Fifth Down. This week I also look at how the Chargers can be so dominant statistically yet only have two wins to show for it. It's something more in depth than my usual lead-ins for the game probabilities.

Here's an excerpt along with a graph I did not include in the original post:

"Successful plays are not enough. Consecutive successes are required to win.

...Two equal teams could each have 12 first downs in a game. One team could have three drives of four consecutive first downs, each leading to a touchdown, and the rest of its drives could be three-and-outs. The other team could have 12 drives consisting of one first down followed by a punt. Both teams could have equal yards, first downs and efficiency stats, and yet one team could win, 21-0. It’s easy to imagine a game in which one team has many more first downs and yards, but still loses. Could something like this bunching effect be cursing the Chargers?

SR Rankings - Opponent Adjusted

Here is an alternative set of rankings based on Success Rate. (You can learn more about SR at this post, and up-to-date advanced team stats, including SR, are always available here.) Beginning this week, each team's SR is adjusted for opponent strength.

The table below also lists each team's opponent SR, except when playing the team of interest itself, for offense, defense, and in total. I realize this may be a little confusing, so I shaded the columns. The shaded columns represent the team's own adjusted SR, while the white columns represent the team's opponent SR. Each team's total adjusted SR is in the far right column.

Each column is sortable. You can sort by division to see how each team shakes out within its own neighborhood. Note that the three top teams come from the NFC East, and that's not good news for my loyal Washington Post readers.

Washington Post: Where is the Redskins Defensive Line?

Today I've got another post up at the Washington Post's Redskins Insider site. This time I look at how the Redskins defensive line is holding the team back.

• There were many ups and downs in Sunday night's game against the Colts, but one sequence of two early plays completely changed the complexion of the game.
• The Redskins have been lucky with turnovers so far, but you can't count on that luck to continue.
• LaRon Landry is leading the league in tackles, but that's one record a safety does not want.
• Linebackers London Fletcher and Rocky McIntosh are picking up the slack for the DL.
• One key in the Redskins' upcoming game against Chicago will be getting to Jay Cutler. His sack rate is jaw dropping.

Efficiency Rankings - Week 7

Recently, I've received a handful of inquiries about how these rankings work. With teams like the 2-4 Chargers and 1-5 Cowboys at the top of the rankings, that's understandable. I thought it might be helpful to explain some things in plain language.

These are not 'power ratings' or my personal estimations of team strength. They're not necessarily the teams I think will make the playoffs. They are simply rankings in order of team efficiency.

I found that efficiency, more than anything else, correlates with, and is predictive of, winning. So the model focuses on net passing and running efficiency on both sides of the ball. It also considers turnover rates, such as interception per attempt and fumble per play. Penalty yards per snap is also included. All of these factors are weighted according to how well they mathematically correlate with team wins.

What makes this model unique is that it distinguishes between factors that are explanatory (telling us why teams won past games) and factors that are truly predictive (telling us why teams will win future games). For example, turnovers and turnover differential account for a very large part of why teams won previous games. But turnovers are extremely random from week to week, and teams are not consistent from one part of the season to the next. They're obviously not entirely random. (Peyton Manning will never have a 4% interception rate--3% is league average), but a very large part of the variance in interception rate can be accounted for by randomness. In other words, Eli Manning might have a 3.9% interception rate so far this year, but it's far more likely that his future games will be much closer to the league average of 3% than they will be to his current 3.9%. So factors like interception rate, which are relatively random, get heavily discounted in this model, especially early in the season.

Punt of the Year

The impact of every play is amplified in overtime, even punts. During the Patriots OT struggle with the Ravens last Sunday, punter Zoltan Mesko may have made the punt of the year. Facing a 4th and 6 from their own 16, Mekso was called in try to bail out the Patriots.

Typically, punts from that region of the field net about 39 yards, putting the Ravens at their own 45, and it looked like the Ravens were going to win the field position battle. From there, it only takes one or two first downs to move into striking distance for a game winning FG attempt. When Mesko trotted onto the field, the Patriots' win probability (WP) was 0.33.

Mesko’s punt went for 65 yards, aided by wind and by poor fielding by the Ravens returner. When the ball came to rest on the Baltimore 19 yard line, the Patriots had gained the upper hand with a 0.54 WP. The punt was worth +0.21 Win Probability Added (WPA), an impact extremely rare for a punt that neither results in a long return nor a fumble.

Tackles By Position

In researching my weekly post at the Post, I took a look at team tackles by position. In the off-season, I created a nifty stat called Tackle Factor (TF--available at the individual stats pages) that attempts to make sense of tackle statistics. Conventional tackle stats can be very misleading. Porous defenses allow more plays than stout defenses, creating additional tackle opportunities for below-average defenders. Additionally, some positions should be expected to have more tackles than others.

I wanted to see how the Redskins' defensive lines were performing. I figured that the larger the share of a team's tackles that a line accounts for, the better it's probably playing. I created the list below, which shows the percentage of tackles by each position group for each team.

Obviously, there is going to be some expected differences between defenses that are primarily 3-4 schemes and primarily 4-3 schemes. This is due to the relative number of defenders at each position and each position's role in the respective schemes. Additionally, the numbers can be skewed by late-game strategies of either running out the clock or desperation passing. Still, we might learn something by looking at where the tackles are being made.

The Weekly League: Notes and Ideas for Week Six

This week's edition of The Weekly League features:

1. Some notes on the peculiar joy derived from the current iteration of the San Diego Chargers, a team whose generic win probability (GWP) surpasses considerably its actual win-loss record.
2. An examination -- via some white-hot tables -- of the NFL's luckiest and unluckiest teams (as measured by GWP versus current, actualy win-loss records) through Week Five.

and

3. A table that proposes to offer something called "EPA Standings" -- itself an idea of minimal importance -- followed by even less important comments.

Let The Weekly League into your life, America!

As usual, a glossary of all unfamiliar terms can be found here.

Idle Thoughts on the Chargers
As our fearless leader Brian Burke noted recently in these electonic pages -- and as reader James noted even more enthusiastically in the comment section -- the San Diego Chargers are frigging awesome right now. The team currently sports a GWP of 0.81 -- this, despite an underwhelming strength of schedule (as suggested by the team's 0.42 opponent GWP). They feature one of the league's better defenses and the best offense.

Roundup 10/16/10

NFL Forecast has fresh playoff probabilities.

Peter King smartly uses efficiency stats (and not total yards or points--awesome!) to diagnose the Saints' troubles this year.

What are the odds?

I recently read this over at Cold Hard Football Facts: "Running is part of football. Always has been, and always will be. The problem from an analysis standpoint is that no one has come up with a way to demonstrate how running helps teams win. But that’s a shortcoming of NFL analysts, not a shortcoming of the running game." Hopefully, now there is one fewer shortcoming.

Platooning QBs? One year when I was at Navy we did that. We had one QB who was a passer who played between the 20s, and one guy who was the runner to played near the goal lines. I think we went 1-10 that year, with the only win against Army.

Last week was a bad one for #1 pick QBs.

Don't sleep on the Titans this season.

Over at the Community site, Chris Alan gives updates his analysis on surviving in a suicide league. Have your own research or analysis you'd like to share? Send it in to Advanced NFL Stats Community.

Washington Post: Redskins Analysis for Week 6

Today I've got another post up at the Washington Post's Redskins Insider site. This time I looked at a number of different items.

• Find out where McNabb and the rest of the offense stands in terms of one of the most predictive stats--yards per attempt.
• Read about possibly the nuttiest 4th down analysis I've ever made.
• Part of the reason for Washington's success so far this season has been thanks to the deep ball.
• How big was Clay Matthews' injury midway through the game? Huge.
• The 'Skins shouldn't fear the Colts this Sunday.

Team Rankings: Success Rate

Most readers are familiar with the weekly efficiency rankings, but that's not the only way to get a sense of team success. Another way is by looking at Success Rate (SR). SR is only counting up successes and failures, so it excludes the magnitude of play results. The more random types of outcomes, such as turnovers and very long plays are counted only as a single success or failure, no different than a 6 yard gain on first down or a stop on 3rd down. It also considers a successful red zone play no differently than one at midfield.

As I've been playing around with SR, I've noticed a few things. First, it correlates well with winning. And second, it correlates well with itself, meaning it is relatively stable throughout the season. These are the two attributes we want in a stat for it to be predictive of future outcomes. I'll have a future article that goes into this in more depth.

Game Probabilities - Week 6

Weekly game probabilities are available now at the nytimes.com Fifth Down. This week I also lead-in with a short discussion of how the Giants defense has outshined that of the Jets. I also shamelessly tout the prediction model's performance from last week.

Efficiency Rankings - Week 6

Two of the top three teams lost but still kept their spots. San Diego, in particular, lost to a far weaker team, but did so thanks to special teams play. One criticism the system receives is that it doesn't include special teams.

It's not that special teams don't matter or can't affect game outcomes. The reason they're excluded from the model is that they are wildly inconsistent from week to week. So while their explanatory power can be significant, they are not predictive. And because special teams performance is not predictive, is it really a mark of good or bad team? Or is it just randomness, subject to a handful of non-repeating plays in each game, of which there are only 16 in a season?

Todd Haley: Advanced NFL Stats Coach of the Week

On the road against the heavily favored Colts, Chiefs head coach Todd Haley began the game with some unconventional calls and received some heavy criticism. He started the game with a surprise onside kick and went for it on 4th down on the Chiefs first offensive drive.

The surprise onside kick is, statistically, almost never a bad idea. At the start of the game, we can just use expected points to analyze the decision. Surprise onside kicks are recovered 60% of the time. Last fall, I wrote (forgive the self quote):

What Is the Break-Even Run Success Rate?

I've been looking at run Success Rate (SR) lately, and it appears to be a fairly important indicator of team success. But if I said that a particular team's run SR was 45%, how would you know if that's any good? It's less than 50%, so does that mean it's bad? So I decided to plot Expected Points Added (EPA) against SR to find out where the break-even point is.

When I plot run EPA per play vs. run SR (for 2000 through 2009), the break-even point is where the best-fit line crosses EPA/P axis--just above 41%.

How Accurate Is The Prediction Model?

A frequent question around here is 'What's your prediction model's accuracy?' The answer is that it varies from year to year, depending on how the schedule works out, with some random chance thrown in. In some years, there just happens to be more evenly-matched games, and in others there are more mismatches.

What's more important, at least in terms of accuracy, is what's called calibration. For example, when the model says a game is a 60/40 game, I actually want the model to be "wrong" 40% of the time. I want an accurate estimation of the game odds more than favoring the eventual winner.

Fortunately, reader 'K Rich' tracked the model's performance since 2007 and sent me a thorough spreadsheet, and the chart below illustrates the model's calibration results.

2010 Play-by-Play Data Posted

Play-by-play data from weeks 1 through 4 is now available. Happy crunching.

The Weekly League: Notes and Ideas for Week Five

This week's edition of The Weekly League features:

1. A thought about Randy Moss from St. Isaac the Syrian.
2. A rudimentary, deeply flawed, but maybe still somewhat meaningful attempt at separating running backs from their offensive lines (and vice versa).

and

3. About as much je ne sais quoi as is safe for an adult human to experience in one sitting.

Soak in the joy, America!

As usual, a glossary of all unfamiliar terms can be found here.

A Note on the Randy Moss Situation

As you are undoubtedly aware, Randy Moss was traded this week from New England to Minnesota. Why was he traded? Well, the popular narrative, which is probably accurate, is that the Vikings were in desparate need of a competent wide receiver and that New England (led by their unfeeling robot-coach Bill Belichick) is a team with almost zero tolerance for distraction. Which, that (i.e. a distraction) is what Moss had become recently, wondering aloud (and very publicly) about his future with the Patriots. (Also, it appears as though Moss got into a halftime argument with quarterbacks coach Bill O'Brien, even as the team was on its way to a convincing victory at Miami.)

The problem with this type of story is the amount of noise it creates. A brief glance at the sporting section of Boston.com (the Boston Globe's homepage) reveals no less than eleventy articles on the subject. These articles make precisely the points you'd expect them to, and a number of others that I, for one, would prefer they didn't. Tony Massarotti, for example, states that now the Patriots will "seek to reclaim the magic and karma that made them the preeminent franchise in football."

Magic and karma -- along with grit, sticktoitiveness, and a can-do spirit -- are the abstract concepts to which sportwriters appeal when they're unable to identify the underlying causes of the phenomena they're attempting to describe. Which, it's fine not to know the answer, but the responsible thing -- veryveryvery obviously -- is to say "I don't know."

In any case, the best lesson on the subject -- it almost goes without saying, really -- is from seventh-century anchorite St. Isaac of Syria. We learn the following from St. Isaac's Wikipedia page (which is, itself, obviously infallible):

Washington Post: Clinton Portis' Misleading Stats

Today I've got another post up at the Washington Post's Redskins Insider site about how misleading Clinton Portis' rushing yardage totals are. He's managed to post some impressive totals, but he's been a net drag on the Redskins' offense during his tenure in Washington. With his recent injury, it gives the Redskins the chance to reevaluate their running game.

Game Probabilities - Week 5

Weekly game probabilities are available now at the nytimes.com Fifth Down. This week I also lead-in with a short discussion of how home field advantage affects different types of match-ups.

It's Blocked!

How often are field goal attempts blocked? And how does the rate vary by attempt distance?

I received a few requests to answer those questions after Monday night's field goal block for a touchdown return by the Patriots. It would also be a consideration in the final seconds of the Colts-Jaguars game Sunday afternoon.

Moss to Minnesota

Randy Moss goes back to the Vikings. Here is his career trajectory, since 2000 anyway. If he continues to be a deep threat, in addition to his own production, he would open up more opportunities for the other Minnesota receivers, and even for the running game.

Week 5 Efficiency Rankings

A lot of movement in the rankings this week. The Giants catapult to #2 on the backs of the Bears who fall from #1 to #9 thanks to that historic beat-down Sunday night. That kind of performance will be hard to repeat

San Diego's offense does not appear to be missing Vincent Jackson one bit, and their pass defense is giving up the second fewest yards per attempt. The model heavily regresses team stats, particularly so early in the season. Nevertheless, the Chargers look like a team about to rattle off a bunch of wins.

Two of the curiosities are the Cowboys and Redksins at #4 and #5. To figure out whey they're so high, all you need to do is scroll down to the team stats at the bottom of the post. Both teams are throwing the ball very well, and they've played against tougher-than-average opponents. Keep in mind these rankings aren't about who has won the most games in the past, but who is likely to win the most games in the future.

The End-Game in BAL-PIT

There were two critical decisions at the end of the Ravens-Steelers game Sunday. The first was a 4th down call, and the second...was also a 4th down call, but not the kind I usually harp on.

Down by 4 with 2:44 left in the game, John Harbaugh made the right call to go for the touchdown on 4th and goal from the 2. The fade pass to Anquan Boldin was unsuccessful (are they ever?), but Baltimore went on to win anyway. I won’t bore you with the actual numbers, but this is a perfect example of why going for it is usually the better call. Even when the play fails, it’s far from a death sentence.

The second and more interesting 4th down call came with 1:15 left. The Steelers faced a 4th and 10 from their own 3. An NFL statistician-emeritus asked me if the right call would have been to take an intentional safety. My first reaction was, ‘of course not.’ That cuts the lead to 2 points, making the lead vulnerable to a FG. I thought, what’s harder to do, drive 40 yards for a TD or drive 25 yards for a FG? Little did I know I was falling into the same trap many coaches do.

How Coaches Think: Run Success Rate

Before tools such as EPA and WPA were available, I relied on team efficiency stats to estimate team strength. Yards per pass attempt or per run attempt worked out to be very good estimators of how good a team was, especially if ‘good’ is defined as being likely to win forthcoming games. Efficiency stats had the added benefit of being relatively simple, widely available, and easy to calculate.

Efficiency stats also worked well in regression analysis. In a regression model, it’s best if the predictor variables are independent of each other. In other words, the less each predictor variable correlates with the others, the more valid and reliable the resulting model will be. Passing and running efficiencies in the NFL correlate weakly. Over the past 10 seasons, offensive passing and running efficiencies for each team correlate at 0.09 (where 1 would mean lock-step correlation and 0 would mean complete independence.)

Live WP Graphs + Updates Are Up

Live WP graphs are up and running for today's games.

Almost forgot. Mobile WP graphs are running too.

Advanced stats for individual players and teams are updated following the 1 pm games.

Roundup 10/2/2010

Are Hall of Fame coaches really just products of great quarterbacks?

You've heard of WOWY stats (With Or Without You), like hockey's adjusted plus/minus. Now here's a WOWRM stat: With Or Without Randy Moss. I did something (primitively) similar with Troy Polamalu last season.

Gregg Easterbrook thinks the 3-4 defense is part of a cyclical fad. He also says that good players are far more important than schemes. He's right. The small advantage I found for the 3-4 is just that--small. The rest of the variance in performance among defenses has to be attributed to other things, most notably player ability. On the other hand, every advantage counts, no matter how slight.

The Weekly League: Notes and Ideas for Week Four

This week's edition of The Weekly League features notes on Sunday night's game between Chicago and the New York Football Giants. It also features some idle thoughts on American filmmaker Woody Allen. I apologize for that in advance.

The Four Factors you see below represent each team's raw performance thus far in four important categories (pass and rush efficiency, pass and rush efficiency against) relative to league average (where 100 is league average and anything above is good). They're only for this season's first three weeks of games, however, so some regression is likely.

Along with the Four Factors, you'll see two other numbers: Generic Win Probability (GWP) and Game Probability (PROB). The GWP is the probability a team would beat the league average team at a neutral site. It can be found for all teams here. The PROB is each respective team's chance of winning this particular contest. Your host, Brian Burke, provides PROBs to the New York Times each week, and those numbers (along with methodology) can be found here.

Finally, a glossary of all unfamiliar terms can be found here.

Some Notes on Football and "High Culture"
It's very possible that you, reader, have one or more objections to American filmmaker Woody Allen. It's also very possible that your objections to Mr. Allen and/or his work are entirely reasonable. I don't care to dispute that notion.

What I'd like to submit is that one of Mr. Allen's strengths -- and I think it's indisputable -- is both his ease with high culture and his ability to mock it simultaneously. (Basically his entire filmography is a testament to this notion, although, if you're looking for examples, the Marshall McLuhan scene from Annie Hall is a strong one.) At his best, Allen is teaching us an important lesson -- namely, that we ought to be curious about, and humble before, the Great Works, but also that, insofar as everything is fallible, so are the same Great Works.