Comments on Advanced NFL Stats: Drunkards, Light Posts, and the Myth of 370

"I'm not sure why it would be incorrect t...

2011-09-19T21:30:59.891-04:00

"I'm not sure why it would be incorrect to exclude Eric Dickerson from this analysis..."

It's pretty safe to assume that, yes, there's something different about both Eric Dickerson and Macintosh computers. But when you exclude someone or something from an analysis, you're also declaring that your conclusions are inapplicable to any person or thing that shares whatever properties made the original person or thing excludable. If that property is being a Mac, then the analysis remains useful to people with non-Macs, assuming they're not somehow unclear about what type of computer they have.

With the "curse of 370", however, the basis for excludability is whatever it was that made Eric Dickerson so amazing, and we can theorize all we want, but we'll never really know what that was. More importantly, we can't know ahead of time (if ever) which current running backs share the same properties.

One related question, if you happen to see this, B...

2010-10-23T15:10:35.124-04:00

One related question, if you happen to see this, Brian. Have you ever checked to see if some of the other "magical" thresholds in the statistical analysis of sports -- e.g., 27 years as the age when MLB players decline on average -- suffer from the multiple-endpoints problem?

I realize this comment is a little late but... you...

2010-10-23T13:00:32.521-04:00

I realize this comment is a little late but... you blew my mind with this blog post, Brian!

2010-10-23T12:46:15.046-04:00

This comment has been removed by the author.

I'm not sure why it would be incorrect to excl...

2010-08-17T14:27:49.357-04:00

I'm not sure why it would be incorrect to exclude Eric Dickerson from this analysis. Isn't it possible that Dickerson had some confluence of events that enabled him to sustain higher carries for multiple years? (A better offensive line, an ability to avoid straight-on hits, fewer pass receptions, less usage as a blocker, improved training methods, biological differences, etc.)

Let's say we are doing some kind of analysis of computer viruses. Wouldn't it be logical to exclude Macintosh computers from this analysis since Macintosh has a substantially lower rate of infection? Couldn't we assume that there must be something different about Macintosh computers that makes including it in the analysis unhelpful?

Now Cold Hard Football Facts has a myth of 400 ht...

2010-03-29T14:59:52.047-04:00

Now Cold Hard Football Facts has a myth of 400

http://www.coldhardfootballfacts.com/Articles/11_3157_Stop_running_back_abuse!.html

Or, I should say, I challenge you to submit such a...

2010-02-19T01:54:47.838-05:00

Or, I should say, I challenge you to submit such a paper to a refereed journal.

Writing the paper would be easy.

"Did RBs not named E.Dickerson see a consider...

2010-02-19T01:54:16.721-05:00

"Did RBs not named E.Dickerson see a considerable dropoff, on average, on their yards/number of TDs a season after having carried the ball more than 370 times ?

Yes : See Greg's comment."

I challenge you to write a scientific paper where you get to drop a data point just because it tends to hurt your theory.

Great article. What's particularly noxious ab...

2010-02-19T01:50:30.862-05:00

Great article.

What's particularly noxious about "the curse of 370" is that you see a lot of commenters viewing the number as a magic curtain, as if something suddenly and dramatically happened with the 370th carry. You'll see fans start saying things like "he's on a pace for 375, I hope he just slows down a little bit", as if those final 10 carries really constitute the straw that breaks the camel's back.

I realize that, and maybe I am unusual in this res...

2010-02-18T17:52:37.098-05:00

I realize that, and maybe I am unusual in this respect. But for me, the first time that I read through it not realizing that, my perception of the situation was different based on those graphs.

My point was that moving the baseline is one way to be tricky with graphs. Bar graphs that start at a high number do the same thing (they can make 10,500 look (relatively) a lot higher than 10,100).

I don't see how that would mislead anyone. It&...

2010-02-18T12:32:37.111-05:00

I don't see how that would mislead anyone. It's relative change in performance, not absolute performance that's important.

While I'm not sure either way on "370&quo...

2010-02-18T11:11:34.662-05:00

While I'm not sure either way on "370". I find it amusing that where you talk about using statistical trickery, you show a graph that is not centered around zero, but -0.5, and have not bolded the zero line.

The media LOVES to use the multiple endpoint selec...

2010-02-09T14:31:17.348-05:00

The media LOVES to use the multiple endpoint selection bias. Think about how often you hear "this team won 2 of their last 3 games"... when this also means (probably) that they went just 1-1 in their last 2 games and 2-2 in their last 4. LOL.

Why are we using the following season as the sole ...

2009-12-10T21:14:42.786-05:00

Why are we using the following season as the sole indicator of RB overuse? If there is some magic number of carries that causes a RB to perform poorly the next season, wouldn't it also cause a drop-off in performance for the remainder of the current season? Where are the charts showing a RB's decline in ypc on a game-by-game basis within a single season once he starts approaching 350-375 carries (adjusting for opposing run defenses, of course)? After all, it is not logical to assume that the effects of overuse on a player are delayed by 8 months (except if he had surgery in the offseason).

Statistics are junk for this sort of analysis. Wh...

2009-12-07T05:59:09.555-05:00

Statistics are junk for this sort of analysis. Why? No matter how many ways we look at it, there is no simple route to the truth because football is a complex game. The stats will be confounded by the continual addition of complex variables. In such cases, the usefulness of statistics deteriorates and what we have instead is an exercise in critical thinking whereby stats are just a tool for aiding the process of dicision-making.

We would all agree that the nature of football is violent and chaotic, yes?, and that winning, game-planning, and team management are a random art defined by chance. If chance favors the prepared, as it does, then the teams that prepare best for chaos and randomness will prevail, because that is what the sport of football is. All teams have depth at all positions becuase injury is expected to happen, players are expected to wear down to the point of needing replaced for the purpose of winning. A RB is trying to help his team win on his 1st carry and on his last. Some RB's are encouraged and given the opportunity to try harder (more carries) because thereby their team views the win to be more likely. That is, the win TODAY, not next week, and especially not next year. If a player amasses a statistically high number of carries, it happened as an anomaly in a season where he was expected to be a vital contributor to help his team win week after week after week. We cannot attach the same expectations (whether + or -) to the same guy in a different year as a simple matter of deduction. His stats will be different. We can reasonably infer 'how different?' by knowing the mean from which the player differed. Defining the mean is a mess all it's own.

Right, but it does actually bring some interesting...

2009-11-26T01:43:12.563-05:00

Right, but it does actually bring some interesting questions into consideration.

I tend to believe that the ability to avoid injury is likely a quality of an NFL player. Perhaps this attribute is a low one -- as in it only controls 5% of injury likelihood -- but I think most of us agree that running style, etc. probably make this a tangible idea.

FO says that the more carries a player gets, the more likely he is to get injured in the future. However, I say -- citing regression to the mean -- that with each carry a player receives that doesn't result in an injury, that player's avoid-injury attribute should actually increase in his favor (ie, he is less likely to get hurt) since he's continually distancing himself from the NFL injury-per-carry average.

A study into this would be impossibly difficult, but perhaps a light sifting through carries-per-injury could help shed some light on this. Do you have access to, or have a database that tracks NFL injuries?

Technically correct, but the difference in regress...

2009-11-25T15:59:19.304-05:00

Technically correct, but the difference in regression strength between a 344 carry guy and a 380 carry guy would be minuscule.

Excellent point from the above poster. Real quick ...

2009-11-25T15:42:10.129-05:00

Excellent point from the above poster. Real quick on regression to the mean. Assuming a 370+ carry ballcarrier and a 344 carry ballcarrier both had the same YPC in the same season (in order to have the same population mean and standard deviation), the 344 carrier will regress to the mean moreso than the 370 carrier since the sample size (344 compared to 370) is smaller, giving more weight to the population mean.

I would say another point in disproving the so-cal...

2009-11-12T22:38:37.791-05:00

I would say another point in disproving the so-called 'curse' would be that the player was one year older the year after his 370+. When a player is 22 & 23, one year is not a huge deal. When a guy is 27, 28, 29+ (like Alexander + Martin, to name a few), that one year can be a very big deal.

And there are more players than Earl Campbell who disprove it. Ladainian improved from his 2nd to his 3rd year. Terrell Davis had 369 carries in '97, and only missed out on 370 because the Broncos clinched their playoff seed and he sat out week 17, then proceeded to play in four additional playoff games. The next year he rushed for 2000+ yards. Emmitt Smith improved after seasons he had 365 carries and 368 carries. He then played in two playoff games after each of those years (I mean, surely playoff carries ought to count in these calculations. I'm sure the hits still hurt!). These are just recent players too. I'm sure there are other cases as well.

Dude, lighten up. I just wanted to take that whole...

2009-10-05T08:29:01.846-04:00

Dude, lighten up. I just wanted to take that whole issue out of the discussion of the example I offered.

For a guy who is into stats, this comment "st...

2009-10-05T01:27:31.545-04:00

For a guy who is into stats, this comment "steroids guys excluded" was a tad disappointing. Here you are talking about working within known data and all of that and then you drop the most extreme example of assumption without data in pro sports - steroid use directly giving power hitters an advantage (as opposed to the other myraid possible factors - like simple weightlifiting (not common in baseball until the late 80s), smaller ballparks, expansion, radar-gun based pitching evaluation, pitchers using 'roids etc).

I don't see the real problem here. FO says : &...

2009-09-30T05:47:32.384-04:00

I don't see the real problem here. FO says : "Don't expect a better/comparable (fantasy) season from a RB that carried the ball more than 370 times the previous year".
Well, surprise, it works ! What's the deal about it ? They never pretended that 370 was a turning point, they even joked about it. They did cherry pick on purpose, and put a fancy name on regression to the mean and RB overuse to sell a concept that ended up being useful to fantasy football players.

In summary :

Is the "Curse of 370" a viable statistical analysis ?

No.

Did RBs not named E.Dickerson see a considerable dropoff, on average, on their yards/number of TDs a season after having carried the ball more than 370 times ?

Yes : See Greg's comment.

In the end, do the target audience (Fantasy Football players) can use this "theory" effectively ?

Yes.

And it's all that really matters. You're not playing in the same field than FO on this one, and you started that by looking at YPC, and not total yards/TDs, which are the basis of FF.

What FO basically did is that to sell this theory better, instead of "creating" "The Curse of Regression to the Mean and RB Overuse in a Given Year", they found a number (370) that worked well, and published a "mystical" "Curse of 370". That's it.

Greg-Thanks for the comment. The reason is very si...

2009-07-27T22:44:25.209-04:00

Greg-Thanks for the comment. The reason is very simple: It's regression to the mean. Consider a slugger in baseball who has a career year. He hits 50+ homers (steroids guys excluded). Very, very rarely would we ever expect for him to repeat, much less improve on that.

Unlike baseball where at bats are capped at 4 or 5 per game, RBs get a lot more carries when they're doing very well. So there is a strong correlation between high carry years and career YPC years.

We're not seeing the effect of a handful of extra carries from 8 months ago. We're seeing the common and natural return to earth from phenomenal career-type years.

While your analysis is good, it doesn't explai...

2009-07-27T22:38:43.658-04:00

While your analysis is good, it doesn't explain away the fact that 370 + carries have occurred 28 times and only one time did attempts rise the following year. Only once did rushing yardage rise the next year. And never has rushing TDs increased (or even remained static). The average drop the following year is 137 carries, 687 rushing yards and 7.3 TDs. So while you can find fault with the analysis - the fact is no one has ever had a better fantasy year rushing the ball following a 370 carry season.

Matty-Yes, I agree you would find significance the...

2009-07-23T18:40:21.504-04:00

Matty-Yes, I agree you would find significance there. I also found very strong significance for % of punts out of bounds for punters with names that begin with A, B, or C.

The point is that you can find significance between two groups in just about anything if you get to pick where the cutoff (or endpoint) is.

Set your dummy variable to 375 or 365, and watch what happens to the significance. Poof.