Yes, QB play is MUCH more important than Defense

Posted on February 13, 2013 by Brent

Over at Igglesblitz today, Tommy Lawlor mentioned that QB play and coaching are much more important than people realize, specifically citing the Packers defensive performance and record for 2010 and 2011. Basically, the defense got A LOT worse while the record got better.

Here’s the link.

I figured I’d add some stats to the point to further illustrate it, because it’s both true and very important. Unable to quantify coaching, we’ll focus on the QB.

Here are the charts for both Passer Rating vs. Wins and Yards Allowed vs. Wins.

If you look at the slope of both lines (really the absolute value of each), its clear the above slope is much greater, hence a greater correlation. Note: Tried my best to un-bias the effects of the different scales so it’d be visually clear. Here are the correlation values:

Passer Rating: .67

Yards Allowed: -.376

This is particularly relevant given the Eagles current situation, with QB uncertainty and a defense in need of serious upgrades (or significant improvement in current players). In general, the play of Vick/Foles/Rookie? will be MUCH more important than the performance of the defense next year.

Another somewhat counterintuitive truth (at least regarding the magnitude of the difference in importance). It also means the Eagles could use this draft, free agency, and scheme change to engineer a dramatic defensive improvement and still end up out of contention if the QB play isn’t good.

Field Position Persistence

Posted on February 5, 2013 by Brent

As I mentioned a few weeks ago, there are several reasons to be hopeful that the Eagles can rebound quickly from this year’s poor performance. After going through the stats it seems clear to me that this year the Eagles were a mediocre team will really bad luck (and a lot of injuries).

As evidence, I showed how both the offense and defense we actually ranked in the middle of the pack according to yards for/against. A big difference, however, was the team’s net average starting field position, which was last in the league at -6.67 (So opposing teams, on average, started nearly 7 yards better than the Eagles.) In fact, that was the fourth worst measure of any team over the past 5 years (’11 Colts/Chiefs and ’09 Lions were worse).

This measure is effected mostly by two aspects of the game, special teams and turnovers. The Eagles were terrible at both this year. As I illustrated previously, though, turnovers are largely random, showing little persistence from year to year. Therefore, since turnovers impact field position, we should expect little persistence in the Net Average Starting Field Position measure.

If this too is largely random, then we can expect both the Eagles offense and defense to perform better next year purely as a result of have less yards to go to score (or more yards to go for the opposition.)

Using the past 5 years, I charted each team’s Net Field Position against that team’s same measure the following year. Here is the chart:

The correlation value is 0.14. So some persistence, but fairly small, which is what we thought we’d see.

Over the next few weeks there will be a lot of talk about things like coaching schemes and who stays/goes, but I doubt we’ll hear anyone say the Eagles could keep the same exact team for next year and have a good chance of finishing .500 or better as things like the fumble recovery rate revert to the mean (probably, it’s possible the team will be very unlucky next year but the odds of that are pretty small).

Other notes:

– The 49ers have led the league in net field position in both of the last two seasons. Last year, the 49ers had the highest mark of the last 5 seasons, with a net value of 9.39, which is a massive advantage.

– Over the past 5 years, the Patriots have the best average (+4.13 yards). The only other team above +3 is Atlanta (+3.44 yards).

– Detroit has the worst 5-year average, -2.73 yards. Last year’s Colts had the worst measure for and individual season at -7.26 yards.

– The Eagles 5-year average is -.806 yards.

All data is from Football Outsiders.

Eagles Inefficient Draft Choices

Posted on January 31, 2013 by Brent

Using our chart from yesterday, I went back over the Eagles draft history from the sample time period and separated the “inefficient” picks from the “efficient” ones. Note: After reviewing the chart, I made one change, taking the 4th round WR selection out of the “inefficient” category.

First a couple interesting notes:

– Overall, there are 3310 players included in this analysis. League-wide, just over 42% of these are considered sub-optimal/inefficient picks by our chart.

– Exactly 50% of Eagles draft choices from 1999-2011 graded as sub-optimal.

– This is surprising because in our earlier analysis, the Eagles actually came out as among the better drafting teams in the league (top third, though there’s a big margin of error in those rankings.)

Up until now, this has been a largely abstract discussion, but it’s about to get real. Below is a chart of all of the Eagles inefficient draft picks by our standards. Look on in dismay… Unfortunately, since the Eagles are part of the sample, we can’t really say the team would have been better off if they had never made any of these picks, but it sure seems like that’s the case (it’s an all or nothing decision to use the strategy, so you can’t pick out Shady and Celek and give back the rest).

Remember that I’m not saying all of these are BAD choices, just that for the team to make them, it should have had extremely strong support for why each player was better than the rest of the prospects at his position group. I’m guessing that the Eagles, for the most part, did not apply that standard…though Shady does seem like he may fit that description as I recall him being rated significantly higher than any other RB at the time.

Given a do-over, how many of those picks would you still make?

Also, it sheds some light on supposed draft “steals”. For example, we can all agree that Brent Celek was well worth a 5th round pick (in hindsight). But how much credit should the Eagles get for that selection?

Using our sample, if you selected 3 TEs in the fifth round at random, you would have a roughly 39% chance of finding a “starter” (1-(.85^3)). Not fantastic odds, but pretty good. So was Celek skill or just the result of the overall odds given that the Eagles tried three times to find a TE in the 5th round?

P.S. I forgot to note yesterday that ZERO out of 54 DTs taken in the 7th round from 1999-2011 became starters. The Eagles selected 3 such players.

I know I mentioned yesterday that I would discuss the whole Talent vs. Need philosophy, but I’m going to wait until I can add some more data to the discussion.

Hacking the Draft….Default Positional Targets by Round

Posted on January 30, 2013 by Brent

Yesterday we took a look at the success rates of different positions by draft position and round. Today, we’ll use the chart to go a step further, identifying Position/Round combinations that are clearly sub-optimal and eliminating them. After doing this we arrive at a modified chart that provides some valuable information and can greatly inform draft strategy. Please note that this analysis is based on the general philosophy that says: The draft should be used to maximize talent and increase the overall skill level of the team. Free agency and trades should be used to plug roster holes. I’ll detail why I believe this is the case tomorrow.

First, a few caveats. All of this relies on the assumption that our sample (draft picks from 1999-2011) is representative of draft classes going forwards. This may not be the case, but it’s a fairly large sample and I have no reason to believe it is significantly skewed.

Also, when broken down by position and round, we are dealing with small sample sizes. For instance, our sample has just 10 centers that have been chosen in the 5th round, with just 2 qualifying as “starters”. Obviously, this is not a large enough sample to conclude that 20% is the true probability of finding a starting center in the 5th round. This is a good example of why we are refraining from setting strict rules, instead using it to develop a general strategy.

Lastly, the first round of the draft is fundamentally different from the other rounds, especially in the very early picks. The goal in the first round (especially in the top 10) is to find an elite player, regardless of position. Therefore, as a general instruction for using the strategy we develop here: It should be adhered to more strictly as it gets later in the draft. So picks in the first round should be based largely on scouting and player evaluations, whereas picks in the 7th round should be based almost entirely on historical probability. This is particularly important for Eagles fans, since the team has the #4 overall pick. For that selection, throw this chart away and hope for an All-Pro caliber player at whatever position in which that skill level is available.

The Process:

Here is a sample chart comparing three positions and their associated success rates in each round:

Focus on the first two rounds and think about which positions you would select in both the 1st and 2nd round. While there is plenty of room for disagreement, my personal opinion would be that the DE position is the optimal choice in the 1st, despite the DB position having better odds of success. The reason for this is the relative decline in odds as you move later in the draft. In the second round, the DE success rate is just 36%, whereas DB success is still above 50%. Conversely, LBs are clearly not a good decision in the first round, since the success rate for the position falls off very little as you move into the 2nd round, making a 2nd round LB a MUCH better value than a first rounder.

Using that relatively simple analysis and applying it throughout the draft, we get this chart:

I’ve blacked out areas that, in my opinion, are not good values based on our stats. Consult yesterday’s post if you want to check the odds yourself, but in most cases I just eliminated rounds that offered no better odds of success than later opportunities. Careful observers will note that I could have gone much farther if I applied the relative draft pick value standard to each area. For example, according to the default NFL Draft Value chart, a 5th round pick is worth more than four 7th round picks (a clear example of how flawed the Draft Value chart is IMO). Applying that to the chart, you would obviously rather choose four DBs in the 7th round (9% success each) than one DB in the 5th round (14% success each). However, due to the number of uncontrolled variables and the potential for non-representative samples, we need to be careful not to go overboard and fall victim to false precision.

Now that you know the general idea/process behind the chart, take a minute to look at it and you’ll notice some interesting things (and almost definitely pick up on things that I will fail to mention or haven’t realized).

My takeaways:

– The 5th and 6th round are particularly notable for the small number of positions for which these picks make sense. The 6th round is a relative wasteland, suggesting that at this point scouting means nothing. Therefore, if we stick to the chart, a team should either choose a DT, TE, or G in the 6th round or trade down into the 7th round. Any other decision is an inefficient use of assets.

It’s possible the Patriots realize this, explaining why they were willing to move down a pick in the 6th round of 2011 (trading with the Eagles) for no compensation, in a trade reportedly made “just for fun”.

– This is also a clear illustration of why DEs are so valued by some teams. If you do not choose one in the 1st round, the next opportunity to choose one efficiently isn’t until the 5th round, when your odds of success are just 23%.

– The 7th round might be best used exclusively on the OL. Looking at the odds above, it’s clear that T/G/C have a much better chance of success as 7th round picks than any other significant position.

– RBs are incredibly hard to pick, and it is probably a better use of resources to just sign one in free agency. (Hard to believe for Eagles fans, since both Shady and Bryce were draft picks. These guys are RARE exceptions.)

– WRs are rarely an efficient pick, with just the 1st, 2nd, and 7th rounds as value opportunities according to our chart.

There is plenty more we can do with this information, but I’ll hold off on that until another day. In particular, we can use this to grade teams’ performance over the past decade, which I hope to do soon.

Hacking the Draft…Comprehensive Chart

Posted on January 29, 2013 by Brent

Hopefully everyone has enjoyed the round-by-round breakdown. While there are obviously a number of variables that can’t be controlled for, the pure statistical look at each position group has already provided some interesting insight.

Before I get to the big chart, let me just clarify exactly what I think this type of analysis is good for, then dig into an Eagles example. Feel free to skip to the chart and come back.

The purpose of this is NOT to arrive at a set of rules by which teams should draft players. Instead, it is meant to provide a general guideline, or a “default draft position”. For example, yesterday I said that selecting DEs in the 3rd round is a terrible value proposition according to the data I’ve collected. That doesn’t mean drafting a DE in the 3rd round is ALWAYS a terrible decision, it just means that for a team to make that decision, it must see or know something about the subject player that makes him CLEARLY much better than any other prospect available at that position.

The biggest flaw in NFL draft strategy, as far as I can tell, is each team’s confidence in its own ability to evaluate talent. Regardless of the general manager, every team has historically had a very large margin of error when it comes to talent evaluation. For instance, in the 1st round less than 6 in 10 LBs selected from 1999-2011 had or are having significantly productive careers (according to our definition.)

So what does that mean? It means teams, in general, should be mostly focused on value during the draft, as opposed to parsing prospects. This is perhaps never more apparent than when a team decides to trade up to select someone. Let’s use the Eagles as an example. NOTE: This is a very rough example, with numbers pulled from my ass, and is only meant to illustrate a larger point.

When the team traded up for Brandon Graham, it swapped 1st round picks with Denver and gave up two 3rd rounders as well (moving up from 24 to 13).

At the 13th pick, no DEs had been taken. Between picks 13 and 24, 3 were taken, including Graham. So that means the Eagles, in their analysis, decided that they had to take a DE (will not argue that decision here, though I was mad they passed on Early Thomas, and can produce witnesses that will verify I said that when it happened).

The only way the trade made sense was if the Eagles, in their DE analysis, decided that the odds of Graham becoming a stud DE were MUCH higher than the odds of JPP, Morgan, or Hughes becoming a stud DE. Here is where the “margin of evaluation error” comes into play.

Using our historical draft data, we can calculate the odds of getting a starting DE with a 1st round pick and two 3rd round picks (I realize they were hoping more than an average starter, but stay with me). Using the table below, we can calculate those odds to be 81.5%. Using the Pro Bowl percentages from the earlier tables, we arrive at 37% for the odds of getting a Pro Bowl DE if you select DEs with a 1st round pick and 2 third round picks. So here is the breakdown for “generic DEs”:

– 1st Round Pick – 24% chance of Pro Bowl, 67% chance of starting

– 1st Round Pick and 2 third round picks – 37% Pro Bowl, 81.5% starting.

Please note that this DOES NOT mean the Eagles made a bad decision. Obviously the odds should be better for the 13th pick than for the 24th pick (we’ll get to that another time). It DOES MEAN, however, that the Eagles, in their evaluation of Brandon Graham, should have been almost certain that he was more than 37% likely to be Pro-Bowl caliber, and more than 81.5% likely to start.

I have no doubt that they believed this, BUT, if they had applied a margin of error to their own analysis (as any good team should) prior to making the trade, they would have been unlikely to go through with it. Let’s be extremely generous and assume the Eagles front office could peg these odds with a MOE of +/- 15% (WARNING: overly simplified statistics). That means if they estimated Graham had a 90% chance of starting, his true odds of starting were almost definitely between 75-100%.

Immediately we can see an issue. Even giving Graham incredibly high odds of starting (90%, which is more bullish than any team should be with any players outside the top few picks) and the Eagles a very generous MOE (+/-15%), the resulting range still does not exclude the 81.5% starting odds for the generic position of a first and two thirds (although it is near the bottom of that range).

That means the Eagles really should NOT have been (though I’m sure they were) confident that Graham would be better than just taking whichever DEs were available at #24 and in the third round, and hence, should not have made the trade.

I don’t mean to suggest that trading up is never a good idea, simply that the evaluative bar for whichever prospect is the target must be EXTREMELY high, and much higher than the standard currently being applied by most teams.

My final point: Teams do not appear to take a probabilistic approach to drafting (which they almost certainly should), and I would guess that they do not actively overlay a margin of error onto their evaluations. This is very much a “new-school vs. old-school” issue, similar to the statistical revolution in baseball, but IT IS NOT THE SAME. It is largely a matter of GMs being willing to recognize and account for their own shortcomings and cognitive biases. The franchises that can apply this will, in the long run, be more successful than those that don’t. (Looking into which teams might be using this type of strategy will be another day’s post)

Ok, enough talk. Here is the chart with every round included. I removed the All-Pro and Pro Bowl columns to make it easier to compare. Dig into it and see what you think. Later this week we’ll mine it for an “optimal default strategy”.

More on Kick Returns

Posted on January 25, 2013 by Brent

GUEST POST (Jared):

This one is shorter and just as interesting, I promise.

In response to a comment on yesterday’s post, I took a deeper look at the stats to see which teams were best at kick returns.

Remember, we looked specifically at ‘touchback-eligible’ returns, meaning kicks that traveled into the end zone and were brought out. We examined these situations because they are instances where returners have to make a choice on what to do. Our initial analysis of this past year provided a couple of insights.

– Kick returners have a good sense of when to run the ball out of the end zone, providing their teams, on average, better field position than just taking a touchback. This persists even on kicks landing deep in the end zone, and even when adjusting for the risk of turnovers (but not injuries). Therefore, players returning kicks deep in their own end zone are, in fact, probably making the right decision.

– However, the Eagles performed both significantly worse than average and significantly worse than if they had just accepted a touchback every time. This raises questions as to why (Boykin’s decision making, coaching, talent, etc.).

But, another question came up. How much better are the best teams at making these decisions? The graph below is a repeat of one of our initial graphs, but with all NFL teams included alongside the Eagles and the NFL average.

The best teams, the Jets, Broncos, and Vikings, averaged over 0.80 Expected Points, significantly higher than both the NFL average of 0.45 and the touchback value of 0.34.

When we look at the return distribution for these successful teams, we can see why this is the case and why their Expected Points are so much higher than the Eagles.

It may be hard to see on the page, but notice all the kick returns beyond the 30 yard line?

The Jets, Broncos, and Vikings all have a good chunk of returns that go farther (even some touchdowns between then) than the 30.

You’ll notice that the Eagles have none.

Therein lies the difference. Kickoff returns can have a decent degree of variance, and the overall performance of your return game hinges on the idea that you’ll bust some long returns over the course of the season.

The best teams do that more often, and this year, the Eagles never did.

But the results here got me thinking again (they tend to do that). If the Vikings, Broncos, Jets, or other teams are so good at returning kicks, shouldn’t they be returning them more often? And shouldn’t teams with poorly performing special teams take a knee more often?

If teams are behaving logically, we’d expect to see a relationship between return effectiveness and return percentage.

So what do we see?

Looks like a relationship to me.

Generally speaking, the better you are at returning kicks, the more often you do it! (I guess the reverse causality is also possible, but that seems much less likely).

We don’t see all that many weird looking outliers here, although a couple of cases are circled that are worth mentioning.

At first glance, it looks like several teams should be returning the ball more often. The Jets, Vikings, Colts, and Broncos. Are there reasonable explanations for why these teams didn’t return more kicks?

With the Broncos, you may have already guessed what’s at work. Elevation.

Unfortunately, there are a lot of kickoff instances that are only listed in the Play by Play as ‘touchback’ without detail on how far the ball traveled. I’d infer that most of these are kicks in Denver that simply are put out the back of the end zone given the high altitude. It’s a shame, because it looks like Denver is pretty good at returning kicks.

The Colts also appear to have some explaining to do. With such a high Expected Points average, why wouldn’t they return the ball more? Looking at the data, it seems like they’ve rotated kick returners. Earlier on in the year, through week 12, they had five different returners who combined to average just better than a touchback in terms of Expected Points.

But for the last few weeks of the season, Deji Karim took over and broke a number of long returns including a 101 yard TD against the Houston Texans. Their boost came late in the year, and they didn’t have enough time to start moving their return %.

I thought the Vikings case would be easily explained by Percy Harvin getting injured, as he’s a fairly dynamic kick returner. However, the team’s touchback % on eligible kicks didn’t change after he left the lineup and his replacement also did an above average job. Maybe they should’ve just returned more (unless they wanted Adrian Peterson to have as long a field as possible!)

The last one I spent some time investigating was the 49ers. They returned far and away the most touchback-eligible kickoffs, but with roughly average results. What gives?

I assumed it was a combination of Ted Ginn and Kyle Williams just returning everything in sight. But even when Kendall Hunter or LaMichael James returns, they don’t willingly take touchbacks frequently.

Jim Harbaugh has a rep as a great coach, with a keen eye towards in-game decision-making. It wouldn’t surprise me to learn that he’s thought about this issue and for whatever reason has emphasized running kicks out of the end zone all the time. The team is above average at doing so, and does significantly outpace taking a knee every time. But I have to think there’s more at work there for a team to run kicks out of the end zone over 75% of the time.

Next up we’ll return to our historical draft breakdown, this time putting every round together (once I figure out the best way to display it all on one graphic).

Examining Kick Returns (The league is good…the Eagles bad…very bad.)

Posted on January 24, 2013 by Brent

Guest Post (Jared):

WARNING: This is a long one, so wait until you’ve got more than a couple minutes. Or, if you’re struggling to kill time at work, you’re welcome.

As everyone knows, this year the NFL altered its kickoff rules, with the goal of enhancing player safety (and looking past the obvious contradiction with a game that emphasizes hitting people). As it was explained, kickoffs are a type play uniquely suited to injuries, as you essentially take two full teams of players and have them run at each other with a huge head start to build up speed. Concussions galore (remember Jason Short?)

That general conversation got me thinking about kickoffs more generally. Simply put:

Does returning a kick make sense?

When you receive a kickoff, there are really on 4 potential outcomes, only one of which involves any decision making:

1 – It’s an onsides kick and the kicking team is trying to recover it…let’s ignore these

2 – The kick goes out of bounds, incurring a penalty, or through the back of the end zone for a touchback…let’s ignore these too

3 – The kick is fielded short of the team’s end zone, and must be returned (you could conceivably take a knee, but that obviously not be the optimal decision).

4 – The kick is fielded in the team’s end zone, and is either downed for a touchback or returned

For this discussion, we’ll focus on number 4, a returner taking the ball out of the end zone.

I felt like there were lots of instances over this past season where a returner would field the ball deep in their end zone and bring it out, only to be stopped short of the 20 yard line (the spot they’d reach with a touchback).

In light of that, I wanted to take a look at the risk-reward trade-off involved in returning kicks out of the end zone.

Sure, a kick return has a small chance of scoring a touchdown, or providing the team with dramatically improved field position (I know that’s hard for Eagles fans to imagine, but I swear it’s possible.)

However, returns also expose teams to a couple additional risks (besides not reaching the 20). The first is a turnover, and a hugely damaging one at that (immediately gives the ball to the other team, who likely just scored, in your territory.) The other, less quantifiable, risk is that the team will sustain an injury. These may occur when the kick returner takes the ball out of the end zone, but not on a touchback, and as such should be considered by whoever is making the decision to return the kick.

So…Do NFL return men suffer from an incentive problem that causes them to behave in a way that reduces the chances of their team winning?

As a theory, it made sense to me. I assume NFL kick returners can maximize their income by scoring more touchdowns (contract incentives can be based on this very metric), whereas no one gets incentivized to take more touchbacks, even if a touchback is a safer decision. So it wouldn’t surprise me to see kick returners taking the ball out more than they should, to try and create the big plays that get them noticed and get them paid.

However, nice theory or not, we needed to actually gather some evidence to see if it’s true (or if when I’m yelling at returners to take a knee, I should probably just keep my mouth shut)

METHODOLOGY

I gathered play-by-play data from this past season (although somehow Week 1 got cut out, so it’s just Weeks 2 through 17). That started me off with over 2,000 kickoffs from across the league (excluding onsides and squib kicks).

I then filtered out any kicks that didn’t make it into the end zone (But since the NFL moved the kicking location from the 30 to the 35, there weren’t as many of those as in years past).

Now, of the remaining kicks, more than half of them were downed for touchbacks (or the kick went out the back of the end zone, which I couldn’t completely control for given the data).

That left me with over 900 instances where a kick returner had the chance to decide whether or not to bring the ball out of the end zone and decided to go for it.

So, all that was left was to figure out whether they made the right choice or not (with one key caveat I’ll describe later)

To do that, I used what football analysts have termed Expected Points (http://www.advancednflstats.com/2010/01/expected-points-ep-and-expected-points.html)

The included link explains the concept much more effectively than I can, but Expected Points is related to the idea that field position matters. Having the ball on your own 1-yard line is much worse than having it at the 50, right? Well, Expected Points attempts to quantify exactly how much more or less valuable a particular spot on the field is (with additional complexity for down and distance).

For example, having the ball in a first and ten situation at midfield is worth 2 expected points. If your team starts in that scenario, in general, you can expect an advantage of 2 points over your opponent. Having the ball in a first and ten on your opponents’ 10-yard line is worth an expected 4.7 point advantage, which makes intuitive sense. The closer you are to the goal line, the more expected points that situation is worth. All values taken from Brian Burke’s model, which he graciously has shared.

On kickoffs, it’s pretty straightforward, because every kickoff will result with one team getting the ball in a first and ten situation.

Now, the model I used for my Expected Points estimates the value of a first and ten at your own 20-yard line (the situation in a touchback), to be worth approximately 0.34 points. That may not seem like very much, but remember, 80 yards on a football field is a long way to go.

With that as our baseline, we can take all the kicks returned and measure the expected points of the results. We also need to be careful of turnovers, because a turnover not only costs you the expected points from your possession, it also provides the opponent with more expected points!

But before we go there, I did mention something about a caveat to this analysis.

Here’s the issue, there’s obviously a bit of bias inherent in this sample. Kick returners, assuming they are well-trained and skilled (basically, not Reno Mahe) should be able to recognize good opportunities to return kicks. We should hope that returners can understand good blocking vs. back blocking and know when to take a knee.

If that were the case (and if my theory about greedy return men is wrong), then we’d expect to see returned kicks having a higher expected points value. Otherwise either the returners are making sub-optimal decisions related to winning the game, or they can’t read their blocking well.

So what is it???

Returns brought out of the end zone are better, providing 0.46 expected points rather than a touchback of 0.34 (sample is over 900 kicks returned).

This implies that returners actually know what they’re doing, and that they recognize when to bring the kicks out vs. when to take a knee. The incentives are not as misaligned as I theorized.

I also looked a little deeper; to see whether kicks farther into the end zone (like 6-9 yards deep) were any different.

Nope, nothing particularly different about them, although the shorter the kick, the better the starting field position when it is returned. But at least based on the data, it seems like returners are actually making the right return decisions.

But wait, there’s just one other thing.

A lot of this perception comes from the games I’ve watched this year. And it just so happens that most of the games I watched featured the Eagles. So what happens when we look at just THEIR performance (ranked near the bottom of the league in average kick return yards)?

Oh dear.

When the Eagles returned kicks this year, and specifically brought the ball out of the end zone, they created an average of 0.16 expected points, significantly worse than simply taking a touchback. Now, a good portion of this score is skewed by one specific play, namely, Brandon Boykin fumbling a kick return against Carolina in week 12. But even when you remove that turnover, the results are still worse than if they had simply taken a knee every time.

The problem becomes even easier to spot if we plot the results of Eagles ‘touchback-eligible’ returns against those of the entire league.

The chart below illustrates the average starting position following kicks into the end zone which were returned, grouped in five yard increments (for example the 45 bin is for all kicks returned between the 41 and the 45 yard line…the 100 bin represents touchdowns)

See how the Eagles have absolutely no ‘touchback-eligible’ returns beyond the 30-yard line (I excluded Boykin’s fumble, which to his credit, was almost in Carolina territory at the time)?

What the team managed to do this year was take a higher-risk, higher-reward scenario, returning potential touchbacks out of the end zone, and collect exactly zero rewards! They would’ve been better off taking a knee on average (note: this assumes your offense is better than your special teams, perhaps a dubious assertion).

It’s hard exactly to know where the blame lies in this situation. Does it rest with the now departed special teams coach Bobby Abril (who, if everyone remembers, was billed as a ‘guru’ level hire when he was brought in from Buffalo)?

Does it lie with Boykin, a rookie kick returner who may have had trouble reading his blocks?

Does it like with Howie Roseman and the administration for an overall lack of depth that kept the Eagles from having a solid set of special teams players?

Maybe a combination of all of the above? (Probably)

The major takeaways from the analysis point to a few things:

– NFL kick returners know what they’re doing, and appear to have a good sense of when to bring the ball out of the end zone, even after accounting for potential turnovers.

– However, the Eagles would’ve been better off taking a knee every time the kick fell in the end zone. The team was SIGNIFICANTLY worse than the rest of the league. This is an underrated weakness of the team and, if it’s addressed, could help the Eagles rebound quickly.

– If the NFL really wanted to limit kick returns, and I’m not sure it did, it probably should have move the touchback spot to beyond the 20-yard line. (To eliminate returns completely, which wasn’t the goal, the league would want to see the Expected Points value of a touchback equal or greater than that of a return in the first chart above.)

Draft History Breakdown – 1st Round

Posted on January 16, 2013 by Brent

Which positions are most likely to fail/succeed when taken in the first round?

I pulled the data and put together the chart shown below. Note that counting someone as a “starter” is a bit subjective. Inclusion in the below data means that a player started for at least 5 years in the league, or if they joined the league less than 5 years ago, has started for more than half the time. However, just because they have started doesn’t mean they have been good. Unfortunately, an analysis that deep will have to wait. For now:

Takeaways:

– It does appear as though the conventional wisdom regarding O-Linemen is correct. They are typically safer picks, as evidenced by the high starter % for G/C/T.

– Choosing a QB is, statistically, a very bad decision. Just 62% of the 37 QBs drafted in the first round ended up “starting” for a reasonable amount of time. However, that number is definitely inflated, as the sunk cost aspect of choosing a QB with a high pick (at least until the most recent CBA) led teams to continue starting players who didn’t deserve to.

Unless you’ve got a top pick and there is a truly incredible prospect, you SHOULD NOT DRAFT A QB. Hopefully Chip Kelly reads this before jumping on Geno Smith at #4. That’s not to say he should draft him, only that he has to be blown away by Smith to make it a reasonable decision.

– LBs have proven to be the most difficult to peg. The position has the lowest rate for starters out of the first round (58%), but the highest rates for All-Pros and Pro Bowls. That tells me LBs are perhaps the hardest players to evaluate coming into the league.

We’ll take a look at the other rounds soon, and eventually put it all together for a complete draft guide, but for now it appears as though there is clear split regarding the odds of success for draft picks (in the first round):

– O-Line, TE, DBs (Safer)

– DEs, DTs, LBs, QBs, RBs (Riskier)

More on Foles

Posted on January 15, 2013 by Brent

After putting yesterday’s post together and getting a helpful twitter suggestion, I decided to take a look at how Foles stacked up against a larger sample of rookie quarterbacks.

I pulled together the rookie stats for every quarterback drafted in the first round since 1999. Including Nick Foles (I realize he wasn’t a first round pick), that gave me 38 QBs. I then eliminated 7 QBs that played in fewer than 5 games in their rookie seasons (Losman, Russell, Grossman, Rodgers, Pennington, Rivers, Quinn.) I did not include this year’s other rookies, as we don’t know yet how their career’s will progress, though it certainly looks like each will be successful.

That leaves us with 31 QB’s. Here is the sample charted by rookie Passer Rating, with Nick Foles in red:

The interesting takeaway is that there are very few “false positives”. Of the 8 QBs with higher rookie ratings than Foles, the closest there is to a “bust” is Tim Tebow, who is still relatively young and has a chance (however slight) to turn his career around. Jake Locker doesn’t really impress me, but he did make progress this year and it’s fair to say the jury is still out on him (also note that he played in just 5 games his rookie year, the minimum for the sample.)

Other notes from that chart:

-Eli Manning’s rookie rating, with 9 games played, was just 55.4.

-Donovan McNabb’s was just 60.1.

Now let’s look at completion percentage:

We see a similar story as with the Rating graph. Only Big Ben, Culpepper, Matt Ryan, and Carson Palmer completed a higher percentage of throws in their rookie seasons.

If Foles had been taken in the first round, there wouldn’t be any talk of even looking at other potential quarterbacks heading into next year. Additionally, he would have played a much larger role in the head coaching search, and we’d be hearing stories of how “Coach X is really excited to work with Foles”.

The fact is, statistically, Foles had a VERY strong rookie season, especially when one considers the patchwork O-Line he was playing behind.

Now I’ll get back to the draft…

Best drafting teams from 1999-2011…

Posted on January 11, 2013 by Brent

Continuing our draft research, I attempted to create a method for determining which teams were the best and worst at drafting over Andy Reid’s tenure, with 2012 excluded since it’s too early to judge most of this year’s rookies.

Before the results, I have to explain how I got there (feel free to skip if you don’t care about the methodology):

First, in order to evaluate players, I used the Career Approximate Value statistic from Pro-Football-Reference.com. This is FAR from a perfect measure, but I don’t know of any better way to compare player production for different positions.

Second, Career AV is a cumulative measure. So players with longer careers will tend to have higher Career AVs. To compensate for this, I divided each players CAV by the number of seasons they were in the NFL. It’s important to note that this skews the data in favor of players who were productive over long periods of time versus those (i.e. Shawn Andrews) who were spectacular for a short time and non-existent the rest.

I then totaled those measures for each team, giving us a rough idea of the amount of production derived from each team’s drafts.

However, we aren’t done yet. In order to adjust for the differing value of each draft pick, I calculated the average point value of each round (according to basic NFL draft chart), then used those measures to calculate the total “Draft Points” used by each team. That way, teams that use a lot of 1st round picks to find production will not be equal to teams that found the same production with lesser picks.

Finally, I divided the Total Adjusted CAV for each team by the total Draft Points used to obtain that production.

The results? Some expected, some shocking. Here are the ten teams (in order) that ranked best from 1999-2011 in identifying and selecting productive players in the draft:

Tennessee, Chicago, Indy, Dallas, Green Bay, Atlanta, Carolina, San Diego, Philadelphia (9th), Houston.

Here are the ten worst (ordered worst to best):

Detroit, St. Louis, Oakland, San Fran, Washington, Minnesota, Kansas City, Cincinnati, Buffalo, Tampa Bay.

Note: This is an attempt to rank teams based on the efficiency with which each used their draft picks.

For the skeptics: A first glance at the best and worst drafting teams would lead one to believe there is a flaw in the methodology. The Titans? Really? On a hunch, I graphed each team’s Adjusted AV/Draft Point (the measure I walked through above) against each team’s wins over the subject time period (Texans not included since they were not in the league for the whole time period). Here is the chart:

Interesting, right? We see a clear positive correlation between the drafting measure we calculated and team performance (wins). Not only that, but it’s a pretty strong relationship (coefficient of .55).

This doesn’t prove the effectiveness of my methodology, but it is certainly what we would expect to see given an accurate measure of drafting skill. Teams that draft better should, on average, perform better on the field.

Here is a graphic showing each team’s Adjusted AV per Draft Point, with the Eagles highlighted in red.

So what did we learn? The Eagles actually have been pretty good at using draft picks since 1999 (and Detroit has been absolutely terrible). Keep in mind that this just measures a team’s ability to find productive players with each pick. It doesn’t account for whether picks achieved success while with the team that drafted them. For instance, the Eagles get credit for Derrick Burgess, even though most of his success came with another team.

Also remember that this is per pick, not total production (i.e. New England had the 4th highest total Adjusted AV, but also used the second most picks to get there).

I’ll be digging further into the data to see what else we can get out of it, but I believe we can drop the whole “Andy Reid sucked at drafting” meme. It’s also a good reminder that as much as some fans hated Reid, over his tenure here, most other franchises were much worse.

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Objective and Analytical Analysis of The Philadelphia Eagles and the NFL

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