Outliers, YPC, and the Cowboys running game

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
We've talked a lot this offseason about the effects of removing Demarco Murray from the lineup and what it's likely going to do to change the sorts of defenses we'll have expected to run against, and the sort of production we're likely to have as a result. I was doing a little bit of research a few days ago on some other RBs who might be available for us later in the offseason here, and came across this article which I thought was pretty interesting. The basic gist of it is that, while a relatively high YPC over a long period of time is a very good barometer of the best backs in league history, statistically, that's maybe a bit misleading because the very highest YPC runs are so very few and far between. As a result, it's a very small number of running plays spread over the course of a long season that separates a productive runner for one who is average or below average.

A case in point from the article, using Demarco Murray as the example:

The best back in the league last year by YPC was Justin Forsett at 5.39 yards. If you remove a mere 9 of his 235 attempts, his YPC drops to league average.

The most productive back in the league last year was Demarco Murray. But take away just 7 of his 393 attempts, and his YPC also drops to league average.

Out of this very simple information emerges a stunning fact: on 386 of Demarco Murray's carries last season, he was indistinguishable from an average back according to YPC.

http://www.arrowheadpride.com/2015/...s-a-future-starter-for-the-kansas-city-chiefs


7 out of 393 plays. That's not very many. That's the number of plays we'd need over league average performance from our RBs to effectively match the sort of production we got from Murray last season. Whether that's coming from the guys on our roster, or instead we're getting it from the passing game where last season we might have run it. The vast majority of the runs we got from him in that fantastic season last season were not outliers, and the pattern more likely correlated with what we might see from other runners.

Now, this doesn't address the dirty runs argument that we've seen so much of. But then those dirty carries are rolled up in the other 386 carries that also happen to be fairly dependent on our ability to execute our blocking scheme effectively. In fact, it might even be the case that we see a higher percentage of these outlier YPC runs from the other backs, both McFadden and Randle have show the ability to that that more often than Demarco did.

What do you guys think? I was surprised how few of an exceptional RBs carries were actually unusual by statistical standards, and how much that affected the estimation of RB performance, overall. This also goes a ways towards explaining why rushing effectiveness might not be all that significant a factor in winning football games. You can easily see the net effect of Murray's 7 outlier runs from last season getting swamped in what would essentially be less than .5 incremental big passing plays/week. With QBs like Romo and Rodgers going up against QBs like RGIII and Foles, that half a big play isn't really that much to make up at all.
 

RoboQB

Well-Known Member
Messages
8,483
Reaction score
10,762
This would be an interesting way to gauge the best big play RBs... set a YPC, say 4.0, and see how many carries have to be taken away
before reaching that YPC.
 

skinsscalper

Well-Known Member
Messages
9,146
Reaction score
5,693
We've talked a lot this offseason about the effects of removing Demarco Murray from the lineup and what it's likely going to do to change the sorts of defenses we'll have expected to run against, and the sort of production we're likely to have as a result. I was doing a little bit of research a few days ago on some other RBs who might be available for us later in the offseason here, and came across this article which I thought was pretty interesting. The basic gist of it is that, while a relatively high YPC over a long period of time is a very good barometer of the best backs in league history, statistically, that's maybe a bit misleading because the very highest YPC runs are so very few and far between. As a result, it's a very small number of running plays spread over the course of a long season that separates a productive runner for one who is average or below average.

A case in point from the article, using Demarco Murray as the example:




7 out of 393 plays. That's not very many. That's the number of plays we'd need over league average performance from our RBs to effectively match the sort of production we got from Murray last season. Whether that's coming from the guys on our roster, or instead we're getting it from the passing game where last season we might have run it. The vast majority of the runs we got from him in that fantastic season last season were not outliers, and the pattern more likely correlated with what we might see from other runners.

Now, this doesn't address the dirty runs argument that we've seen so much of. But then those dirty carries are rolled up in the other 386 carries that also happen to be fairly dependent on our ability to execute our blocking scheme effectively. In fact, it might even be the case that we see a higher percentage of these outlier YPC runs from the other backs, both McFadden and Randle have show the ability to that that more often than Demarco did.

What do you guys think? I was surprised how few of an exceptional RBs carries were actually unusual by statistical standards, and how much that affected the estimation of RB performance, overall. This also goes a ways towards explaining why rushing effectiveness might not be all that significant a factor in winning football games. You can easily see the net effect of Murray's 7 outlier runs from last season getting swamped in what would essentially be less than .5 incremental big passing plays/week. With QBs like Romo and Rodgers going up against QBs like RGIII and Foles, that half a big play isn't really that much to make up at all.

Good stuff, Idgit. Some nice legwork there and it really is eye opening as to what just a couple of plays can do to a season average.

However, just for the sake of playing Devil's Advocate: In a game of, literally, inches those 7-9 carries in a season (or roughly two carries a game) can often be the difference between a win and a loss which, subsequently, can be the difference between sitting at home for the playoffs or a 1st or 2nd seed OR (as we saw) the difference between a Super Bowl, victory or a game ending interception.

What a great freaking game, man. The vast amount of variables that lead to one team's fan base living on cloud nine and 31 other team's fan bases looking back at every play and pondering "what if?".
 

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
Good stuff, Idgit. Some nice legwork there and it really is eye opening as to what just a couple of plays can do to a season average.

However, just for the sake of playing Devil's Advocate: In a game of, literally, inches those 7-9 carries in a season (or roughly two carries a game) can often be the difference between a win and a loss which, subsequently, can be the difference between sitting at home for the playoffs or a 1st or 2nd seed OR (as we saw) the difference between a Super Bowl, victory or a game ending interception.

What a great freaking game, man. The vast amount of variables that lead to one team's fan base living on cloud nine and 31 other team's fan bases looking back at every play and pondering "what if?".

Most definitely. Explosive plays win games, and plus or minus 7 of them can make or break a season. It's still really interesting to think how thin the line is between a below average RB and an above average one.

I do think this illustrates why teams defend tendencies more than they defend the players themselves. Sure, offenses have some of their tendencies *because* they're taking advantage of great players, but there's also that clear element of 'this is what we do, and we can do that with more than one guy on our roster if we have to.'
 

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
So 7 runs set him apart. He had 5 fumbles.

That's another factor, right? Those turnovers offset those big positive plays. So you can see where a guy who doesn't pop big ones but doesn't fumble the ball might well be comparable to a guy who does break more long runs but who fumbles at a higher rate. It's pretty interesting.
 

AzorAhai

Well-Known Member
Messages
6,511
Reaction score
8,901
I think it goes into what the realistic fans have been saying. We will be fine as long as the commitment to the running game stays intact.

I posted in another thread, but it got buried so I'll post it here. 23 teams had 1600+ yards rushing. 21 teams averaged 4.0+ ypc. None of those other teams have the Cowboys OL who excel in the run game. There are not 23/21 elite RBs in the NFL, yet those teams all managed to be effective.
 

Crown Royal

Insulin Beware
Messages
14,229
Reaction score
6,383
I've seen the analysis and think it is a good barometer, or at least contributory, to show what a running back is good at. That being said, I am of the opinion that a big-play run is, for the most part, an overrated aspect of the offense and a running back in general (big play being a run of over 25 yards).

The value in Murray was not so much his individual big plays or ability to go for over 5 yards a play, but his ability to fit in and inform the system we ran. The though has been that the days of the running game are over, but I can't overstate enough the effect of being able to run 30+ times per game and continue to do so effectively for 4 yards each and ever time, with few negative or <3 yard runs. When the other team knows that you can consistently get 3 yards at will even without a hole and you are committed to doing so, thus staying ahead of the chains, then the tempo and strategy of the opposing defense automatically changes. That's why Romo went off the way he did at the end of the year - the league had said ENOUGH - we are not going to let the Dallas running game beat us. And two things happened - first...we STILL ran effectively despite completely stacked fronts (although with much less success), and Romo enjoyed throwing against single coverage and small fronts for the final 8 games.

Murray fit in because he was able to be the guy everyone keyed in on. When you don't have a committee, but a single individual who represents the running game, it tends to stick in the defense's mind. You aren't focused on stopping the run game - you're focused on stopping Murray, a powerful and physical runner who wants the contact.

Something that would be interesting in this analysis is negative runs - how many do you take away (once the top runs) to show above average?
 

T-RO

Well-Known Member
Messages
15,077
Reaction score
16,851
The basic gist of it is that, while a relatively high YPC over a long period of time is a very good barometer of the best backs in league history, statistically, that's maybe a bit misleading because the very highest YPC runs are so very few and far between. As a result, it's a very small number of running plays spread over the course of a long season that separates a productive runner for one who is average or below average.

Sorry this is incredibly flawed.

If you want to glean something meaningful take the top 10 runs away from EVERY runner and then compare them.

Even the guys averaging pedestrian numbers had some long runs.

You boys understand the difference between average and median, right? There is a very important distinction between these two math terms and people often don't get it.

Yes it would be interesting to compare the MEDIAN runs of all backs in the league. I don't know if that stat exists.
 

skinsscalper

Well-Known Member
Messages
9,146
Reaction score
5,693
Most definitely. Explosive plays win games, and plus or minus 7 of them can make or break a season. It's still really interesting to think how thin the line is between a below average RB and an above average one.

I do think this illustrates why teams defend tendencies more than they defend the players themselves. Sure, offenses have some of their tendencies *because* they're taking advantage of great players, but there's also that clear element of 'this is what we do, and we can do that with more than one guy on our roster if we have to.'

Which is exactly why I'm not hand-wringing over the RB position right now (and obviously neither is the team). We are a power running football team. Murray or not. It's what we do and what we will continue to do regardless of who is back there.
 

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
I think it goes into what the realistic fans have been saying. We will be fine as long as the commitment to the running game stays intact.

I posted in another thread, but it got buried so I'll post it here. 23 teams had 1600+ yards rushing. 21 teams averaged 4.0+ ypc. None of those other teams have the Cowboys OL who excel in the run game. There are not 23/21 elite RBs in the NFL, yet those teams all managed to be effective.

Unless, of course, what you field is way below average. The 13 plays for Davis to get to league average in the article, for example...some of those might kill possessions. It really is a game of inches. But, yeah, given adequate blocking that ought to be way above league average for rushing plays, the backs would have to be pretty bad to still perform that much below league average for the position group.
 

Tabascocat

Dexternjack
Messages
27,783
Reaction score
38,827
CowboysZone DIEHARD Fan
Ok Idgit, go look at all of the 1-2 yard runs for that crucial first down and compare them to the other NFL running backs. I will await your answer in a week or so :D

It is those "dirty" yards that worry me, not the rest though.
 

Beast_from_East

Well-Known Member
Messages
30,140
Reaction score
27,231
The issue is that you cant just cherry pick which runs to throw out because when games are so close now days with many decided by a FG or less, those 7 plays might account for 2 extra wins a season. We won the East by 2 games last season, so you might be talking that 7 plays is what separates the division winners from division losers.

So yes, maybe 6 or 7 plays separates the top backs from the average backs but those 6 or 7 plays contribute directly to more wins, that is why the top backs get paid so much more than average backs. Otherwise, why would any team pay big money for a RB if they are all just about the same?

NFL teams are not stupid, there is a reason backs like Forte, Foster, Peterson, and Murray make huge dollars while other backs make peanuts.
 

YosemiteSam

Unfriendly and Aloof!
Messages
45,858
Reaction score
22,189
CowboysZone LOYAL Fan
On the other side of the equation is the ability to break the big play is what separates the average backs from the good ones. How many big plays did the average running backs make?

You say 7 and 9 plays, but is it that they broke 7 and 9 *more* big plays than the average back?

Not trying to discredit as I don't know their actual stats or the stats of the average running back. It would be interesting to look though. Something clearly set them apart. Even if it was just 7 or 9 plays respectively.
 

Corso

Offseason mode... sleepy time
Messages
34,768
Reaction score
63,194
The issue is that you cant just cherry pick which runs to throw out because when games are so close now days with many decided by a FG or less, those 7 plays might account for 2 extra wins a season. We won the East by 2 games last season, so you might be talking that 7 plays is what separates the division winners from division losers.

So yes, maybe 6 or 7 plays separates the top backs from the average backs but those 6 or 7 plays contribute directly to more wins, that is why the top backs get paid so much more than average backs. Otherwise, why would any team pay big money for a RB if they are all just about the same?

NFL teams are not stupid, there is a reason backs like Forte, Foster, Peterson, and Murray make huge dollars while other backs make peanuts.

That's a good point, except for the fact that NFL teams with their "professionals" muck up all the time in player acquisition.
All the time. Almost every year. By almost every team. I'm excited to watch how this upcoming season unfolds.
 

Crown Royal

Insulin Beware
Messages
14,229
Reaction score
6,383
I have to also think that the number of carries has a big piece of it, in any statistical system, the larger the sample the more you are going to regress to the mean.

In other words, the fact that he has more carries means that he contributes more to the mean of the entire sample, thus of course he is going to get closer to it.
 

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
Sorry this is incredibly flawed.

If you want to glean something meaningful take the top 10 runs away from EVERY runner and then compare them.

Even the guys averaging pedestrian numbers had some long runs.

You boys understand the difference between average and median, right? There is a very important distinction between these two math terms and people often don't get it.

Yes it would be interesting to compare the MEDIAN runs of all backs in the league. I don't know if that stat exists.

The idea isn't to take runs away from players to somehow minimize their performance. It's just to illustrate how few plays are actually outliers in terms of their effects on YPC, so discussions around the import of YPC come packed with that volatility in terms of averages baked in.

If we weren't already using averages as the measure of effectiveness (yards/carry), then maybe it would be more interesting to see the median data.
 

AzorAhai

Well-Known Member
Messages
6,511
Reaction score
8,901
Unless, of course, what you field is way below average. The 13 plays for Davis to get to league average in the article, for example...some of those might kill possessions. It really is a game of inches. But, yeah, given adequate blocking that ought to be way above league average for rushing plays, the backs would have to be pretty bad to still perform that much below league average for the position group.

I don't think the RBs they have are in the bottom 1/3rd of the league so I'm content to go with what we have. The teams on that list were surprising. Even some at the top didn't have what most would even consider "good" RBs. Throw in the OL and I think we can get 1800 yds and 4.2+ ypc. If we get around that, I'm more than happy. If there is a weakness, it is the short yardage situations. That would be my only concern right now. I would be more worried about that if the empty set with Beasley and Witten wasn't so hard to stop.
 

Idgit

Fattening up
Staff member
Messages
58,971
Reaction score
60,826
CowboysZone ULTIMATE Fan
I have to also think that the number of carries has a big piece of it, in any statistical system, the larger the sample the more you are going to regress to the mean.

In other words, the fact that he has more carries means that he contributes more to the mean of the entire sample, thus of course he is going to get closer to it.

Yeah. It's far from an exhaustive or comprehensive measurement of anything. I think we all know intuitively that Randle's 6.7 YPC from last year (or whatever it was) was a function of the small sample size.

It's just a snapshot, really, of how the big runs affect YPC in a league where YPC is considered the quick-measure of a running game's effectiveness.
 
Top