Nick Foles and Interception Index Regression

Nick Foles and Josh McCown were two of last season's most pleasant surprises, emerging from obscurity to post two of league's most efficient seasons.  Both finished in the top 3 for Expected Points Added per Play, largely in part because the two combined to throw just three interceptions.

With one week of the 2014 season in the books,  Foles and McCown have already matched that combined total.  While everyone should have expected both to regress from their remarkably turnover-free 2013 seasons, that does not tell us how far each should regress based on historical norms.

Bayesian Draft Prediction Model

Let's say you're a GM in need of a safety. You really like Ha Ha Clinton-Dix (FS Ala.) but are unsure if he'll still be on the board when you're on the clock. Do you need to trade up? How far? What if you're a GM with a high pick and would be willing to trade down if you're still assured of getting Clinton-Dix? How far down could you trade and still get your guy?

I've created a tool for predicting when players will come off the board. This isn't a simple average of projections. Instead, it's a complete model based on the concept of Bayesian inference. Bayesian models have an uncanny knack for accurate projections if done properly. I won't go into the details of how Bayesian inference works in this post and save that for another article. This post is intended to illustrate the potential of this decision support tool.

Bayesian models begin with a 'prior' probability distribution, used as a reasonable first guess. Then that guess is refined as we add new information. It works the same way your brain does (hopefully). As more information is added, your prior belief is either confirmed or revised to some degree. The degree to which it is refined is a function of how reliable the new information is. This draft projection model works the same way.

The 2013 ANS All-Analytics Team

The All-Analytics team returns. Like always, the awards are predominantly based on pure numbers, specifically Win Probability Added and Expected Points Added. The chart at the bottom of this post is provided for easy reference. It plots regular season WPA and EPA for the top 32 players at each position. You can look at past seasons as well. The players closest to the top right corner are the leaders at their position. That chart is available with running totals throughout the season in the Tools | Visualizations | Position Leaders link in the menu.

Without further ado, here are the 2013 awardees. Winners receive an invitation to play nerf touch football in my backyard. Airfare and hotel are not included. Click on the position headers to see the full stat table for each position.

MVP

Obligatory Manning-Brady Post...But This One Is Cool, I Promise

The risk of injury aside, it's inevitable we'll see either Manning or Brady in this season's Super Bowl. These two great players will be linked for all of football history. Even advanced stats aren't going to separate their performance from their teams'--the numbers are only the start of the conversation, not the end. But as long as the conversation is going to happen, we might as well start with the best numbers.

The interactive visualization below chart's each player's career. It's a special version of the QB viz I update weekly throughout the season. In this edition, I've selected only Manning and Brady for comparison, plus I've included postseason data.

The viz offers two unique and innovative ways of looking at each player, unashamedly stolen from the best baseball analytics site on the Web, Fangraphs. First, there is a plot of career cumulative Win Probability Added (WPA) from each QB's first year through his most recent year. It's an interesting way to compare the career trajectories of top passers because it's a cumulative chart.

Second, there is an "Nth best season" Expected Points Added (EPA) chart, which takes some thinking to understand because it's not plotted in chronological order. It plots each QB's season in order from his best EPA season through worst EPA season. It's not cumulative and because it appears to trend downward does not mean the QBs are declining. I like it because re-ordering each season makes the separation between each player's performance clear to see.

Tony Romo and High Variance QBs

It's too bad we won't get to watch Tony Romo play for the N.F.C. East championship Sunday Night due to injury, because he always seems to add drama to a game. Just look at his last two starts. In week 15 he helped blow a 23-point halftime lead with a -0.13 Win Probability Added (WPA) performance, but in week 16 he threw the game-winning TD pass in the final seconds and put up a +0.64 WPA performance to keep his team's playoff alive.

Romo has a reputation as a choker, mostly due to his team's late-season under-performance. But taken as a whole, his numbers are very "clutch." He has ranked 8th, 5th, 6th, 3rd and 12th in QB WPA over his last 5 (non-injury seasons). I don't buy the choker label, but I do buy the notion that he's a gambler and an improviser, which can cause wide swings in his game-to-game WPA numbers. So I thought I'd pull the stats and investigate how Romo compares in terms of his game-wise variance.

Variance measures how wildly a stat changes. In this analysis, I measured the variance of week-to-week WPA. If a player has lots of heroic games and lots of calamitous games, his WPA variance will be high. If a player is relatively consistent from week-to-week, regardless if he is consistently good or consistently bad, his WPA variance will be low.

For those who are unfamiliar, variance is an average of the squared deviation from each player's mean WPA. For statistical sticklers out there, I used variance of a population rather than variance of a sample--otherwise players with relatively few starts would have a slightly inflated result.

This season, Romo ranks only 14th in game-to-game WPA variance out of the 41 QBs with 200 or more qualifying plays. He's also 14th over the past 5 seasons. If we go back to 1999, the earliest year of my data, he ranks 9th out of the 101 QBs with 800 or more qualifying plays. His early career was apparently very boom-and-bust.

Here are a three tables of QB WPA variance. The first is for the 2013 season through week 16. The second is for the last five seasons. And the third for the period 1999-2013.

Brady vs. Manning: Who Really Has the Upper Hand?

There are lots of different ways to measure who truly has "the upper hand" in the Tom Brady-Peyton Manning rivalry.  Brady supporters will cite his teams' 9-4 head-to-head record as the decisive edge, while the Manning camp may point out that their quarterback has the better stats over the 13 meetings.  These arguments dovetail with each quarterback's general reputation—Brady as the winner, Manning as the stat-sheet stuffer.

Of course, neither Brady nor Manning play defense, so a "head-to-head" comparison is a bit short-sighted to begin with.  Jake Plummer was 2-0 against Brady, and Jay Fiedler put up better numbers in his four head-to-head matchups against Manning.  Somehow, I doubt a "Fiedler vs. Manning" post would generate much debate.

So how do we begin to truly evaluate which quarterback has performed better in 13 Manning vs. Brady games?  Well, let's start by looking at their WPA, EPA and passing success rate (SR) during each of their games:

The Myth of Playoff Peyton

Let's play a quick word association game.  I say "Peyton Manning in the playoffs," and you tell me what images your mind conjures up.

For someone who may be the greatest quarterback in NFL history, the picture isn't quite befitting. You probably imagined something like Peyton hanging his head in the snowy Foxboro winter, or slumped over following his pick-six against the Saints in the Super Bowl.  Or perhaps just a general expression of chagrin, like the hilariously petulant "Manning Face."

Yes, Manning does have a losing record in the playoffs for his career (though only eight have had more wins, but who has time to split hairs?).  The next time Manning loses a playoff game will give him the record for most career playoff losses, and fairly or not, that will always be a part of his legacy.

Most rational fans realize that Peyton has only thrown up a handful of postseason clunkers, and that such a small sample size should not significantly affect his standing as an all-time great.  They might defend by saying, "Yeah, Peyton's been a bit worse in the playoffs, but his regular-season numbers are so great that it doesn't matter."

Actually, even that statement would be false.  What people fail to realize is that Peyton has not been any worse in the postseason.  In fact, one could make a fairly convincing argument that he's been one of the two or three best playoff quarterbacks of this generation.

To illustrate this point, let's take off our "Embrace Debate" hats and let the numbers tell the story.

The Truth Is Tony Romo Isn't a Choker

Last week, a premier quarterback threw a devastating fourth-quarter interception that effectively sealed his team's fate in a back-and-forth game.  This critical gaffe perpetuated what has become an increasingly disturbing trend of failures to "come through in the clutch," as critics like to deride.  Despite gaudy statistics, he has a recent track record of playing his worst in big games, raising questions as to whether or not his team's so-called championship window remains open.

Clearly, Tom Brady is the NFL's biggest choke artist.

That last example is just one way real and armchair analysts alike can place selective focus on certain facts to create a skewed perception.  Perhaps no player has had more damage done to his reputation in this manner than Tony Romo.  Romo played the game of his life against the Broncos last Sunday before a single ill-timed mistake reignited accusations of "choking."  As Grantland's Bill Barnwell put it, Romo did not have a perfect game, but rather the "perfect Tony Romo game."

But what does that even mean?  Most people know that Romo is not really as bad as his choker reputation implies.  More sensible fans may even understand that Romo receives far too much blame for the organizational and team-wide failures of the Cowboys.

However, do people know that Tony Romo may actually be the most clutch quarterback in the league, or at least very close to it?  To answer this, let's delve into the murky depths of "clutchness" through a couple different lens.

Position Leaders Visualization

I made a Tableau viz to illustrate last season's ANS Player of the Year Awards. The idea was to see just how far from the pack the very top performers stood at each position. For fun I also included previous seasons. Now I've finally gotten around to setting up an automated update process so that we can see the position leaders as the season develops. The viz is permanently available under the Graphs | Visualizations | Position Leaders menu link. Like the other visualizations, it will

It's no surprise where Peyton Manning ranks, but check out LeSean McCoy on the RB page. One thing you can use this plot for is to see which teams, players, and squads are likely to regress. for example. If you look at the QB chart, you can see that Cutler, Tannehill, and Locker have WPA numbers that far exceed what we'd expect given their EPA numbers. Recall that they each had game-stealing TD passes so far this season, inflating their WPA. It's likely that they'll return to earth over the course of the season and we'll see their respective logos drift down toward the trend line.

Likewise, we would expect guys who can produce yards and points but not a lot of WPA to drift upward on the WPA axis. This would include Newton, Romo, Eli Manning, and Ponder (if he recovers from his rib injury and gets his job back). I guarantee it!*

*Guarantee not an actual guarantee.

Trent Richardson's Game by Game Advanced Stats

Here they are from last season, and here they are for 2013.

Not spectacular. It's a team sport, and these are team numbers. But Richardson's stats don't show any indication he's a game changer. He was 72nd in the league with -19.7 EPA and 58th with -0.03 EPA/P. When you watch him, he's hard to bring down, and occasionally gets a yard or two more than a typical RB. But when a team spends a first round pick on a RB, it should expect more than just a couple of extra yards per game than typical.

Last season IND was 7th in run EPA/P and 9th in run SR, so this trade could be a fun experiment in isolating the value of a RB from the rest of the offense. We'll see.

Point / Counterpoint on Rodgers' Extension

Today we're going to try a new format here at ANS--a debate between me and myself on the market value of Aaron Rodgers' recent contract extension. Rodgers recently signed a deal adding 5 years to his current contract. This will pay him roughly $21M per season over the next 3 years. See if you can figure out which Brian has the right idea and why they get different results.

Brian 1: Rodgers' new deal is a fantastic bargain. He's one of the truly elite QBs in the league today, and guys like that don't grow on trees. But more scientifically, just look at this super scatterplot I made of all veteran/free-agent QBs. The chart plots Expected Points Added (EPA) per Game versus adjusted salary cap hit. Both measures are averaged over the veteran periods of each player's contracts. I added an Ordinary Least Squares (OLS) best-fit regression line to illustrate my point (r=0.46, p=0.002).

Rodgers' production, measured by his career average Expected Points Added (EPA) per game is far higher than the trend line says would be worth his $21M/yr cost. The vertical distance between his new contract numbers, $21M/yr and about 11 EPA/G illustrates the surplus performance the Packers will likely get from Rodgers.

(This plot includes for all free-agent or veteran extensions since 2006. Cap figures are averaged for each player's career and, to account for cap inflation, are adjusted for overall league cap ceiling by season. Only seasons with 7 or more starts were included.)

What is Ed Reed's Going Value?

Last year I looked at the salaries of free agent safeties to estimate the going rate based on production stats.  FA safety salary correlated fairly well with production, specifically +EPA (positive Expected Points Added). With Ed Reed, one of my favorite safeties, on the FA market at moment, I thought I'd take a look at what would be a fair market price for his services in 2013.

Here, price is defined by salary cap hit. NFL salaries are notoriously complex with bonuses and guarantees. But these are boiled down into a single cap number, which is the cost to his team's overall salary cap, the most precious resource it has in acquiring and keeping players.

The analysis here produced the chart below. In short, top FA safeties are valued at about $2.0 million for every +EPA per game, minus $170k.

For example, for a guy who produces 2.1 EPA/G, his going rate would be about $4M per year. So where would Ed Reed stand in this context?

Reed is a future Hall of Famer, but he is now 34 and headed into his twelfth season. Here is how his total production and per-game production have tracked over the course of his career. (Note that all stats  are for regular seasons only. +EPA stats can be found here.)

2012 ANS Awards

I'm going to come at these year-end awards from a slightly different angle. The modern NFL has made the QB position so singularly important that any honest, realistic award for MVP would simply go to the top QB of the season. Not only is that boring; it also says nothing about the QBs themselves--just about how central the position has become.

As always, WPA and EPA will be my measure of performance, rather than yard or sack totals. I'm going to look at how each player stacks up against their peers at the same position. The idea is a little like the concept of the replacement player. The most valuable player would be the one that offers the most value above the next best alternative. Still, because the effect of the passing game is so magnified in today's game, this would always be the number one QB. So let's put each position on the same level and see who most stands out above the pack.

Rather than stare at an eye chart of numbers, I made a visualization that plots the top 32 performers at each position. Each player's total WPA is plot on the vertical axis and total EPA is plot on the horizontal axis. I'm not looking at over- or under-performance like when we were looking at 'clutch' play. In this analysis, I'm just looking for the players who show up at the top right of the plot. All numbers are from the regular season only.

There are two additional tabs that simplify things a bit by ranking each player by WPA and by EPA.

And because it's easy and fun, I've included past years too. You can even select 'all years' and see the top 32 at each position since 2000. The WPA Rank and EPA Rank bar charts are especially cool because they identify performance on multiple teams according to team color.

Cam Newton: The Best First Two Seasons Ever

This Sunday, Cam Newton will finish his second NFL season. As the final whistle blows in the Panthers' final 2012 contest against New Orleans, Newton will have finished the greatest first two seasons we've ever seen out of an NFL quarterback. And at least in the realm of the regular season, it isn't particularly close.

Newton enters Sunday with the following career statistics: 574-for-969 passing (59.2 percent), 7,672 yards, 40 touchdowns, 28 interceptions; 246 rushes for 1413 yards (5.7 per carry) and 22 more touchdowns. Newton's 8,584 net yards -- including 70 sacks taken for 501 lost yards -- the Panthers star has an exactly 800 yard lead on Peyton Manning's old 7,784 net yardage mark, the previous best for any quarterback in his first two seasons. Newton still has one game left.

Newton's 7.9 yards per attempt ranks fourth (Ben Roethlisberger, Dan Marino, Mark Rypien). His 62 total touchdowns ranks second (Marino). Newton's only major category away from the top: a 2.8 percent intereception rate, still 16th of the 78 quarterbacks since 1933 to start at least 20 games in their first two seasons. Only Andy Dalton attempted more passes than Newton of those above him on the list.

How Much Is Joe Flacco Worth?

Joe Flacco is finishing his 5th year in the league. It's a contract year for a QB who remains frustratingly difficult to assess. He shows flashes of brilliance in one game only to be followed by apparent ineptitude in the next. He has the size, the strength, the arm, the accuracy, but there's something missing.

Statistically, he's just as hard to figure out. Among all QBs since 2008, when Flacco entered the league and began his uninterrupted starting streak, his WPA has exceeded his EPA. Of the 30 QBs with the most attempts since 2008, Flacco has the 3rd highest ratio of WPA to EPA. Most observers would call him "clutch."

Based on the recent historical relationship between QB performance and salary, we can estimate Flacco's market value. But depending on how we value his production, we get very different salary values.

Flacco is remarkably consistent. Receivers come and go, and lineman come and go, but since his rookie year Flacco is a rock solid 70 EPA per year guy. Adjusting for team cap inflation, that makes Flacco worth approximately:

One Point Favoring Andrew Luck over Robert Griffin III

Arguments on the Rookie of the Year seem to be favoring Robert Griffin III over Andrew Luck at this point in the season. Griffin's performance has been spectacular, certainly -- he's thrown for 2,660 yards and 17 touchdowns against just four interceptions. His 714 rushing yards on 105 carries translates to a league-leading 6.8 yards per carry, and his 6.5 AYPA is tied with Peyton Manning for third in the league.

Luck runs well, but nowhere near Griffin's standard -- he owns 216 yards on 44 rushes. Luck has thrown for over 900 more yards than Griffin and matched Grffin's 17 touchdowns. But his AYPA is a middling 5.1, 21st in the league and tied with Andy Dalton. Griffin has a 23-point EPA advantage and a 0.09 point per play advantage.

But for those who prefer to use more context-neutral stats -- as opposed to WPA, which has Luck second in the league at 4.32, over 1.5 wins better than Griffin -- there is one point in Luck's favor: the sheer volume of his output.

Washinton's' offense is obviously focused on Griffin, but the team uses the run liberally, rushing over 22 times per game (not counting Griffin's rushes). Alfred Morris carries the bulk of the load, with 1,106 yards (4.8 per carry) on the season. The Colts have rushed just 22 times per game themselves, but they've also run 117 more plays (just under 10 per game) more than Washington, and those extra plays are all directed through Luck and the passing game. All told, Luck has thrown 14 more passes per game than Griffin.

Basketball analysts have picked up on an essential point of the game: as usage rate -- the burden of the offense -- increases, efficiency tends to decrease. Steve Kerr was a more efficient scorer for the 1995 Chicago Bulls -- he shot 52.4 percent from three -- but there was no way he could take 22 shots per game with any efficiency. Jordan continued to excel even when confronted with the most difficult shots -- under duress, at the end of the shot clock, or both.

There's a similar relationship with quarterbacks. The idea that certain quarterbacks can only handle 20-to-25 throws per game with efficiency holds up in the data. Observe, the average yards per attempt given a certain attempt total (data includes all games since 2009):

Powered by Tableau

Washington Post: Griffin Is One of the Biggest Upgrades of the Decade

This week's article at the Post looks at the biggest upgrades and (declines) at QB of the past 11 years.

The biggest year-to-year decline belongs to the Vikings and Brett Favre. Favre’s 2009 season marked an increase in quarterback EPA of 152 points. But as Favre giveth, Favre taketh away. In 2010, the Vikings’ combination of Favre, Joe Webb and Tarvaris Jackson sunk Minnesota with a drop in EPA of 212 points. Favre’s late tears with Green Bay were also a roller coaster. His decline from 2005 and his resurgence in 2007 both rank among the biggest swings of the recent decade.

Also check out this companion post that features each team's year-by-year improvements and declines at QB.

Josh Freeman Discovers The Deep Ball

Tampa Bay Buccaneers opponents are getting used to an unfortunate sight: the Josh Freeman deep ball. Freeman hit on two more 30-plus yard passes against the Chargers in Sunday's victory, this 54-yard dart to Mike Williams and this 31-yard strike to Vincent Jackson.

Freeman has now completed 32 deep passes (at least 15 yards downfield) for 1,064 yards, five touchdowns and just one inteception, accounting for nearly 70 expected points added. All this has come in just 68 attempts -- Freeman is averaging 15.6 yards per deep attempt and over an expected point per throw.

We shouldn't be surprised. Freeman made his way into the first round of the 2009 draft despite mediocre college numbers, mostly thanks to his size and the arm strength that comes with it. He was compared to players like Daunte Culpepper and Ben Roethlisberger -- huge quarterbacks who (at least at one point in their careers) made a living off the deep ball.

For some reason, Freeman and the Bucs never really embraced the deep ball before this season. Freeman went deep on just 14 percent of passes last season, dead last among 39 qualified quarterbacks. He threw deep less often then players like Tyler Palko, Ryan Fitzpatrick, Kyle Orton and Matt Hasselbeck -- inexplicable, given the respective skill sets. Chad Pennington threw 18.7 percent deep passes in 2008, his last full season.

This seems to be the major revelation of the Greg Schiano-Mike Sullivan establishment in Tampa Bay: Josh Freeman has the fabled "big arm," so why not use it? This season, Freeman has gone deep on over a quarter of his pass attempts; his 25.3 percent ranks third in the league behind Joe Flacco and Andrew Luck. The concept isn't particularly difficult -- let Freeman drop back, and if the pocket holds, he has the arm to get it to the receiver down field.

Andrew Luck: Thriving In The Manning Shadow

Andrew Luck capped his first half-season in the NFL with an indisputably great performance Sunday, as his 433 passing yards on 48 attempts (9.0 yards per attempt) and two touchdowns pushed the Colts past the Dolphins, 23-20. The victory pushed what was a hapless Indianapolis team last season to 5-3 and into the playoff hunt. It's unclear if the Colts can keep riding so high -- they rank just 26th in our efficiency ratings and NumberFire has them in the playoffs in 51.5 percent of simulations.

Luck's sharp performance goes beyond just Week 9's effort. He'll enter Week 10 ranked fourth in WPA, eighth in EPA and ninth in EPA per play. His only advanced stat blemish might be his 5.4 AYPA, tied for 16th with Ryan Tannehill and Joe Flacco, stemming from his 30th-place 56.5 percent completion rate. But given the weight placed on Luck's shoulders in this Indianapolis offense -- his 336 attempts rank third in the league.

Given the 14 brilliant years of service Peyton Manning gave the Colts prior to his neck injury and subsequent release, the former Colts All-Pro will constantly be used as a measuring stick for Luck. Just looking at the rookie years, one would imagine Luck will become the greatest quarterback ever. Manning threw a whopping 28 interceptions (4.9 percent of passes) in year one and managed a rough 4.0 AYPA. Many players have posted superior rookie seasons leading into less-than-Hall-of-Fame careers. See, for example, Neil O'Donnell, Jim McMahon, Joe Flacco and Jake Plummer.

As such, it may be more educational to compare Luck to Manning's Colts career as a whole -- or at least the 12 seasons worth of data we have here at Advanced NFL Stats (dating back to 2000). Luck's games are in light blue, Manning's games are in gray and Manning's averages are in Bronco Orange.

Alex Smith: Counterexample

I think that in almost all cases if a young QB doesn't demonstrate consistent above average performance within a couple seasons, he's not worth sticking with. It's very uncommon for a young QB to toil for several years of below average performance and then suddenly blossom into a winner. Coaches and GMs, analysts, and fans alike all make excuses for poorly performing QBs. They have no 'weapons', no line, the wrong scheme, and so on. Those are certainly valid considerations, but it's the QB himself that mostly drives his numbers.

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.