Thank you. The interior vs. tackle distinction is a real value-add.
also duty-free guys falling over and grabbing their shins
Julius Caesar, Commentarii de Bello Civili, Book 2, Chapter 8
Setting. As the 2013 football season rolls on, the problems in Michigan’s run game have become more and more glaring. This has led to much ballyhooing and debate as to the main causes of Michigan’s ground game woes. The most basic argument is whether our problems are caused by weakness on the line or at the running back position. Brian’s UFRs come into play here, and while Fitz and the gang haven’t been perfect by any means, the play-by-play breakdowns seem to suggest that the problem lies with our offensive line. A phalanx our line is not.
Identifying the line as the problem, however, has not really made anyone very content. Rather it’s sparked a debate between the baby blamers – those who see Michigan’s youth as the source of their problems – and the crappy coach contingent – those who find fault with our coaches development of our o-line talent, not to mention play calling.
Previous Work. The MGoCommunity has already produced some solid work on this topic. The Mathlete’s preseason study looked at other teams who had offensive lines with an 1st round NFL pick combined with 2+ freshmen. Although he eventually admitted that we were still probably a year away, his comparison grouped us with the likes of Alabama, Oregon, and Stanford. GuloGulo’s diary from back in September looked at the relationship between average o-line experience in the Big 10 and success mainly defined as yards per play. After the first four weeks of the season, he concluded that we were about average in both experience and success. Gameboy’s recent diaries have shown that Michigan’s line is relatively young whether you take a “number of years in the program” or “number of previous starts” approach.
Questions. In this study I want to delve a little deeper into what we mean by “experience,” what we mean by “success,” and how those two variables are actually related. I will attempt to answer four questions:
Definitions. Neither experience nor success have single and obvious definitions. With regard to the o-line, success could be defined by wins, yards per play, yards per rush, sack percentage, or play-by-play results a la UFR. For the first part of this study, I use yards per carry as my metric for success. Experience, likewise, can be defined in a variety of ways, including the number of years in the program, the number of starts, or the number of snaps. This analysis primarily uses the number of years in the program as its measure for experience. This isn’t because it’s necessarily the best measure – we’ll test that in a bit – but rather because it’s the measure that’s easiest to find information about. Redoing this study with a start- or snap-focused measure of experience would be a worthwhile endeavor. In the graphs below, the year of the players are equated with numbers, so that freshman = 1, red shirt freshman = 1.5, sophomore = 2, red shirt sophomore = 2.5, and so on.
Data. The data for this study are drawn from this 2013 season. All 125 FBS teams are included. The YPC stats come from ESPN and the experience info comes from the a scouting site. Because this isn’t necessarily about Michigan’s o-line this year, but rather about the general relationship between offensive line experience and success, data from any recent season should apply though. Giving this thing some time depth would probably improve its efficacy. The stats are current as of 11/6/2013. All the images are from the MGoBlog flickr account; Bryan Fuller gets the credit, I believe.
This is a primarily quantitative study, but I’m in no way a statistician. My background is in Classics, as in Greek and Roman studies, so although I’ve tried brush up on my stats, there’s certainly the possibility that these metrics aren’t employed or interpreted perfectly. Feel free to correct me.
With that said, it’s probably useful to give a brief overview of the statistical measures in an attempt to describe what they actually tell us. I’m looking at 4 main metrics: correlation coefficient, r-squared, p-value, and slope of the linear trend line.
Correlation coefficient: The correlation coefficient quantifies the degree of linear relation between two variables. The coefficient ranges from -1.0 to 1.0, and the larger the absolute value of the coefficient, the stronger the relationship. This will provide a single number for the strength of the relationship between o-line experience and yards per carry.
R-squared: The r-squared provides a measure for the amount of variance in one variable that can be explained by another variable. This will be used to assess how much of the variance in yards per carry can be explained by o-line experience. It’s important to note here that there are obviously many other factors other than experience that govern running game efficiency (coaching, scheme, running back skill, etc.). A low r-squared doesn’t necessarily mean that experience is unimportant, just that other factors are also important.
P-value: The p-value let's us know whether our results are statistically significant; more specifically it provides a measure to assess whether we should discard the null hypothesis. In this case, the null hypothesis is that there is no relationship between o-line experience and running game success. The p-value ranges from 0 to 1. A small p-value, < 0.05, suggests that we reject the null hypothesis, while a large p-value suggests we retain it. If p-values are low, we should have faith in the relationship between experience and success; if they are high we should feel less confident about that relationship.
Slope of linear trend line: The trend lines in the graphs below show the linear relationship between experience and success. The slopes of that lines indicate the extent to which we’d expect YPC to change as a result of a change in experience. For example, if the slope was 0.5, the data would suggest that an extra year of average o-line experience is worth ½ of a yard per carry.
Good habits formed during youth make all the difference. - Aristotle
The scatter plot below depicts the relationship between average offensive line experience in years and yards per carry. Click for enlarged scatterplot with all BCS teams labeled.
The data broadly confirm what we’d expect. This is good! This means that we’re right in claiming our youth is (partially) the problem. The older your offensive line is, on average, the more yards per carry that team produces. The correlational coefficient is 0.16 for this data set, indicating that there’s a slightly positive correlation between offensive line experience and yards per carry. The r-squared is small, however, suggesting that only about 3% of the variation in teams’ yards per carry can be attributed to the experience of the offensive line. A p-value of 0.07 is marginal, meaning that it’s not particularly clear whether we should interpret these results as significant or not. Let’s start by giving experience the benefit of the doubt though, and for the time we can conclude that experience does indeed influence ground game success. The slope of the linear trend line suggests that an extra year of average experience is worth about 1/3 of a yard per carry.
At first glance, there does seem to be a positive correlation between o-line experience and YPC, although there is still a lot of variance in YPC that cannot be explained by experience.
One of the arguments against the approach taken in question one is that an offensive lineman’s number of previous starts is a better measure of experience than the number of years he’s been in the program. Let’s take a look; the graph below plots this alternate measure of experience against yards per carry. Click to enlarge and see Oregon and Wisconsin put up 6.7 YPC despite having less total starts along the o-line than Michigan.
The relationship between the number of previous OL starts and yards per carry generally mirrors the pattern produced when the number of years in the program is taken into consideration. The correlation coefficient is actually slightly higher (0.23 compared to 0.16), suggesting that starts is indeed a slightly better measure than years in the program for the purpose of predicting o-line success. The r-squared suggests that previous starts can explain about 5% of the variance in yards per carry, and a p-value of 0.01 indicates that these results are indeed significant. The slope of the line suggests that each extra start is worth about 1/100 of a yard per carry, meaning that 50 extra stars is worth about ½ a yard, and 100 extra starts is worth about a full extra yard per carry.
Now that the data show that “number of starts” is probably a better measure of offensive line success, I’m going to revert to “number of years in the program” as my main metric of experience. This is simply due to the convenience of the data. If someone can get number of starts for all the programs, that should improve things. Perhaps another day.
Why doesn't Lewan make everything okay?
One of the most common arguments against using the average or total experience of the entire offensive line is that all spots along the line are not created equal. Lewan being an awesome LT doesn’t help our RG Mags getting crushed by the NT. Essentially, interior line experience is more important than tackle experience. But does it really matter whether your experience comes on the interior or exterior of the line?
Let’s start with tackle experience first. The graph below shows the relationship between the average experience of each team’s tackles and their YPC.
Check out Michigan and Purdue with their bookend fifth year senior tackles. This doesn’t bode well for a positive relationship. Looking across the entire spectrum of the FBS, there appears to be no correlation between the experience of a team’s tackles and their ability to run the ball successfully. Once again, this is good news for us. It’s not that we’re not taking advantage of our great tackles, it appears that on the whole, tackle experience just doesn’t influence ground game success all that much. The correlation coefficient is a measly 0.02, the r-squared is <0.01, and the p-value is 0.81, which is incredibly high. The slope of the trend line suggests a very, very slight decrease in YPC as tackles increase in age, which doesn't make any sense at all.
This is really interesting actually, as all metrics suggest there is essentially no connection between tackle experience and yards per carry. If tackles aren’t the cause of the correlation between total experience and YPC, then it must be the interior of the line, right? Click to enlarge and see us at the children's table with UCLA and Purdue.
It appears as though the “our interior line is full of infants” excuse is actually a pretty good one. With a correlation coefficient of 0.22, the relationship between these two variables is stronger than when offensive line experience as a whole is averaged (in years) and an order of magnitude stronger than the correlation between tackle experience and YPC. The r-squared indicates about 5% of YPC variation can be explained by experience along the interior of the line, and a p-value of 0.01 suggests these results are significant. The slope of the trend line suggests an extra year, on average, is worth about 1/3 of a yard per carry.
If you extrapolate that out over the course of a season, that’s about 150-200 extra yards of rushing per year (Michigan had 502 rushing attempts in 2012 according to ESPN). Interior line experience does seem to be a big deal. Also, we’re one of the 3 youngest teams out of 125 FBS teams in terms of interior line experience. That is young indeed.
The foundation of every state is the education of its youth. - Diogenes
Thus far the data have shown that interior line experience is a better predictor of running game success than total offensive line experience. The next question is whether average interior line experience is a better predictor of success than the “weakest link” along the line. In this case we’ll call the youngest person on the interior of the line the weakest link. This really has nothing to do with their ability, it’s just a measure of their experience in the program. Click to enlarge and see Auburn averaging 6+ YPC while starting a true freshman interior lineman.
It looks as though there is something to the “weakest link” argument. The correlation coefficient in this case is 0.29, which stands as our strongest correlation yet between some measure of experience and yards per carry. The r-squared indicates that this measure can explain about 8% of YPC variation, and a p-value of 0.01 suggests that these results are indeed significant. The slope here once again suggests that an extra year is worth about 1/3 of a yard per carry.
The fact that the age of a team's youngest interior offensive lineman is a better predictor of run game success than its average offensive line experience, or even the average experience of just the interior line, is rather unexpected. This should bode well for Michigan's future along the line as we gain experience and depth in future seasons.
First off, offensive line experience leaves a lot of the variance in yards per carry unexplained. So even though this study supports the conclusion that offensive line experience does indeed influence success in the running game, there are clearly many other factors that also play a role.
In this study, experience has been measured in in two ways, both as “years in the program” and as “number of starts.” While both serve as decent predictors of success in the running game as judged by YPC, number of starts seems to be the better measure. Unfortunately, it’s also the measure that is more time-intensive to track. When looking at the outer vs. interior line, the data suggest that success on the ground is much more closely tied to the experience of the interior line than it is to either the tackles or even the average experience of the line as a whole. Surprisingly, tackle experience seems to be completely irrelevant as a predictor of run game success. Finally, the level of experience of the least-experienced person on the interior line serves as an even better metric for predicting running game efficiency. The “weakest link” argument appears to hold water.
Unit of Measurement
|R-Squared||P-Value||Effect on YPC|
|Total Experience||Years||0.16||0.03||0.07||Extra year = +1/3 yard|
|Total Experience||Starts||0.23||0.05||0.01||Extra 10 starts = +1/10 yard|
|Interior Line Experience||Years||0.22||0.05||0.01||Extra year = +1/3 yard|
|Youngest Interior Lineman||Years||0.29||0.08||0.01||
Extra year = +1/3 yard
What does this mean for Michigan? As Gameboy showed us in his diaries, Michigan is young along the O-Line, whether you’re judging by years in the program or by number of starts. What I hope to have demonstrated here is that (a) being young really does matter, and (b) we’re especially young where it matters most (i.e., tied for 2nd youngest on the interior OL out of 125 FBS teams).
Borges and Funk in happier times
There’s been a lot of heat on Borges and Funk recently, and it’s appropriate to ask whether this study indicts or absolves them. Unfortunately, I think the data tend to side step the question. The fact that o-line experience does seem to influence YPC, and especially the finding that interior line experience seems to be of utmost importance, combined with Michigan’s position with regard to these measures (i.e., they fall almost exactly along the linear trend line in both the interior line experience graph and in the weakest link graph), would initially suggest that the line is performing about as expected.
This doesn't let the staff off the hook. The relatively low r-squared values would indicate that there is a lot more than just experience that goes into producing a successful running attack. Coaching, both in terms of scheme and player development, is probably one of the most influential factors in governing run game success, and this study doesn’t attempt to measure or control for that aspect of the game. Moreover, this study doesn't account for talent along the offensive line, which would probably suggest Michigan is underperforming relative to the recruiting rankings. Strength of schedule is also omitted. Having played CMU, Akron, UConn, Indiana, and Nebraska, adding this variable could also raise our team's expected YPC, and in doing so lower our performance relative to expectations.
According to the eyeball test, the apparent regression along the offensive line would seem to indicate that there are some seriously problematic coaching issues. There are several BCS programs with similar youth-related issues on the interior line, both when experience is averaged (e.g., UCLA) and when experience is defined by the youngest interior lineman (e.g., Notre Dame, Arkansas, and Auburn), and these programs still manage to perform significantly better than us in terms of yards per carry. When viewed within the context of the entire FBS, however, the data suggest that Michigan’s youth is a real and influential issue.
On the bright side, this should give us hope for future seasons. As our interior line matures, both in terms of average experience and in terms of its weakest link, we should improve. This only holds, of course, if all the other factors that go into producing a successful offensive line – namely coaching scheme and player development – are on par with the rest of college football. That, unfortunately, is not guaranteed.
Rome wasn’t built in a day, but it did progressively grow bigger and better until it reached a point where it dominated at the point of attack. Let’s hope our offensive line can do the same.
Awww, come on.
 Actually, upon further review, I’m not so sure this is accurate. Over the course of 8 games, Fitz has 5 positive UFR games, 2 negative, and 1 around zero, while the OL has 5 positive UFR games, 2 negative, and 1 around zero. Obviously RB and OL numbers aren’t perfectly commensurate, but this probably suggests the blame should be shared.
Thank you. The interior vs. tackle distinction is a real value-add.
Another thing I noticed is 1. Michigan is not only inexperienced, but we are also always under the line (which I read as slightly below average beyond inexperience) and 2. we keep running the ball when it doesn't work and that makes me sad.
Thanks akim. Yeah, I focused more on the "Michigan is pretty close to the trend line" aspect in the interpretation, but you're right, no matter how you slice it, we're falling a bit short even when experience is accounted for.
Thanks for all the work that went into this. The data is very interesting and certainly suggests that youth in the interior is a big issue.
I am shocked that OT experience is basically useless. I am interested in the passing game.
However, Michigan is currently ranked 111th in YPC. Just for perspective, the last three teams to finish 111th in YPC are UAB, Troy, and Louisiana-Monroe. This is unacceptable, even if we're starting five pylons connected by kite string. This is Michigan.
Youth is a factor. Coaching, player development, and schemes are factors, too.
After Saturday, it's hard for me to find any excuses for this coaching staff. A performance like that against a team like Nebraska is completely unacceptable. That game, more than any other since Hoke's arrival, is damning to our O-Line coach and our OC. While I agree that we should have been able to run the ball against Nebraska, we couldn't. AB did not do a good enough job adjusting.
Thanks, Ron! Glad to hear you enjoyed it, even if it doesn't make you feel much better about our eleventy first ranking in YPC. And the data I used were pre-Nebraska, so the current picture is even less rosey.
Exactly, there's a difference between a struggling rushing offense that, say, produced 3 yards a carry on average and an abysmal, inept rushing offense that can't get to the line of scrimmage. I have to believe that Michigan's inexperience interior is capable of performing as well or better than South Dakota State's interior.
Yeah, this is essentially my line of thinking as well. A young line suggests you're putting up like 3.5 - 4 YPC instead of 4.5-5 YPC, all else being equal. It doesn't mean you're stringing together multiple negative rushing yardage games.
Good start though. ..."this study supports the conclusion that offensive line experience does indeed influence success in the running game"... I see a couple of common complications in your application of univariate regression, namely (1) an assumption is that the data points exhibit independence (e.g. think of an experiment), this is not "round-robin" tounament data and (2) that undefined confounding variables (e.g. schedules, opponents record may imply a nonlinear relationship with very high YPC against weaker teams...one can propose others). Each case can create the illusion of a relationship. An analysis of the outliers might be worth performing, which might lead to a multivariate approach.
Finally, even if there is correlation, goodness-of-fit does not imply predictability (at least for the individual team). While your p-values are low, your "statistically significant" findings should serve as a basis for further corroborative research rather than for your base conclusion above. In my experience, regression methods are less successful for social-science applications like this than for physical models, where one has control over data acquisition and the experiment itself. It would be nice if it was all about the number of years, or starts, but my guess is that if you explore your outliers it might add more to the discussion.
Thanks for the feedback, Gob. As I mentioned, I'm a humanities guy, so I'm just trying my best with limited stats knowledge. It seems like most of your critiques come down to the fact that there are a lot of other factors that are influential in determining a teams ypc (e.g., schedule, talent, coaching, etc.), and, of course, you're totally right. Even if we take the results as significant, it only goes a little bit of the way towards explaining YPC.
My main hope was that the large sample size (at least relatively large compared to just looking at the Big 10) would help alleviate some of these concerns. We'll get young teams that have played tough schedules and young teams that have played easy schedules, experienced teams with talented linemen and experienced teams with low-profile linemen. Basically operating under the assumption that these things would balance themselves out, and so if the trend holds up with a low p-value we can actually put some faith in it.
I'm planning on looking at pass protection next, but after that I might play around with doing some multi-variate analysis to see if we can increase that r-squared value. Also, I like the idea of looking to see if non-linear models might better fit the data. Thanks again for the input.
I think this is a fun article, but want to ensure that we don't stop the discussion here and assume that as our line ages it will fix everything. That is why an analysis of outliers is necessary.
You wrote: "My main hope was that the large sample size (at least relatively large compared to just looking at the Big 10) would help alleviate some of these concerns."
Keep in mind that p is about sampling error not bias and with larger sample sizes p values will drop even if the data is random. Try this with a coin flip on your own and an abitrary binomial (yes/no) "predictor". Your regression coefficients are already pretty small (e.g. 0.1 or 0.3) and thus near zero, so the p-values need to be really small (not the same argument when your coefficients are larger). The 0.01 value for p being "highly significant" is kind of arbitrary but influences how statistical studies like this one are received.
We need to be careful about judgements in the presence of confounder variables other sources of bias etc. There's a lot of room for disagreement and error. If you have not already done so, I totally recommend David Freedman's 1999 article "From Association to Causation". If you google it, you can find the .pdf online.
In the mean time, keep it up!
So given this information, it would have been incredibly smart to move Schofield to guard. Chalk that up as another failure on the offensive coaching staff.
Having senior tackles appears to be worse for the running game, but it may be better for the passing game. We have to see what the data suggests in Part II.
True. We'll have to see.
Somebody suggested this at least semi-seriously in another thread. At the time I thought it was ridiculous, but the data here suggest it might not have been crazy. Obviously you can't do it with 3 games to go, but it's at least an interesting thought experiment to image Braden and Mags on the outside with Lewan-Glasgow-Schofield on the inside.
You'd have to wonder how much this would cripple the passing game. After all of MSU's stunts and double A-gap blitzes, I wonder if it's less problematic than we'd assume.
Actually, I was very surprised that when they inserted Magnuson into the lineup, they didn't move Schofield to Guard and put Magnuson at tackle. Allegedly Magnuson's going to play tackle next year so wouldn't he be better served by getting experience at tackle, and Schofield played guard before so that wouldn't have been strange for him.
This content is front-page worthy.
Now I have even less hope that the OL can improve this year. IMO, O-linemen shouldn't be counted on to contribute until their third year in the program (e.g. Glasgow, Miller, Bryant) and should be expected to struggle if they play any earlier. Did I expect this O-line to dominate? No, but I expected Lewan and Schofield to make the other linemen better. Should we expect this O-line to struggle? Yes. Did I expect them to struggle to the tune of -69 rushing yards the past two weeks? No, that's where I blame the coaches. The early season plan was to run behind Lewan and Schofield on stretches and counters, getting Toussaint into the open field, where he excels. I think poor TE blocking and Gardner's turnovers caused the coaches to change their plan, and every time they've tried to solve their problems they've made them worse. Also, I think the staff has shown their narrow-mindedness by assuming that the only way to play ball control football is to run between the tackles.
Tackle experience not having any impact on running performance did not pass my intuitive eyeball test. So I think it is good to revisit. Why does run heavy Wisconsin produce so many good NFL ready tackles if they are always a run first team? There are some explainations though.
Are the run assignments for a tackle generally easier? This could explain why a tackles run performance does not increase significantly because they are producing at a high level right away. If this is the case the argument of putting Scofield at guard makes more sense.
Regardless of the macro results the job of a coaching staff is to adjust the game plan to what they know they have. If an individual with a humanities background has made these conclusions and we accept the posulate that they are spot on, it should be obvious to football coaches with decades of experience. This is a huge knock on the staff as if true it should have been making adjustments in August. If not true, their coaching is bad.
This should be bumped.
he keeps calling the same play call, play after play.
Idon't know anything about football, but I knows enough that if sumtin aint working...dont do it!!!
Why doesnt he just run different plays that get us more yards?
So, isnt it weird that the run game (which was bad to start the year) got appreciably WORSE around the time a true frosh and RSFrosh from another position were forced into the inerior OL?
Just a weird coincidence that Borgess' play-calling got that much worse at that same time.
I definitely wanted changes to be made after the Akron and UConn games. Now I imagine most of us wish we hadn't messed with it. Hindsight's 20/20, but it sure seems like the gains in terms of cohesion along an unchanging line would have outweighed whatever benefits (hmmm) we've gained from mixing it up. Here's hoping this widespread experience pays off in future years...
some people are laying the most blame at the feet of play-calling.
Some people justlove to watch the football and scoring points...they don't know that the game is defined by the lines. They think that saying is just lipservice tothe "big uglies" that need more love.
But, the fact remains, offensive line -- especially the interior -- is of HUGE importance to an offense.
The ESPN article is quoted below:
"Of the 20 starting lines from the past 10 Super Bowls, 11 had all five players who started the previous season. Six other groups had just one new face. Only the 2000 Giants -- perhaps the weakest of the bunch -- reached the Super Bowl with a line that had three newcomers (the immortal trio of Lomas Brown, Glenn Parker and Dusty Zeigler). Of those Super Bowl O-lines, almost as many undrafted free agents (21) started as first-round picks (27)."
For the NFL anyway, the first alludes to experience, while the second downplays recruiting.
I've always thought that OL was much harder to learn than most people thought, but probably only because my grandfather drummed it into me at a very early age.
If the interior of the line is of the utmost importance, our coaches failed the team by not moving Schofield back to guard.
So Borges' decision to mess with the line (failure on Borges) after two subpar offensive performances against two of the worst teams in college football (failure on Borges) = Borges not the problem.
The insanity of defending Al Borges' job based on his ability to probably call a play that makes sense most of the time is getting extremely played out.
But if you'd mentioned you were wasting your life pulling experience stats on all 125 FBS teams I could have saved you a lot of time, because I was sitting here doing the same thing.
I've been working on something similar to this, but using reshp's idea of multiplying experience factors across the line instead of adding (the idea was that each player has some probability of failing on a play, you multiply those probabilities to get the overall probability of somebody busting). It's sort of the weakest-link theory but with the understanding that on any given play any of your linemen might happen to be the weakest link.
Hopefully I'll get that post up tomorrow sometime.
Actually, now that I re-read your post, it'll probably be worth cross-checking our data because I got lineups and experience information off the team websites (rosters and player bios, participation reports from games) and it's possible the scouting website got some things wrong. (Rivals has pretty much everything wrong; your guys are probably a lot better).
Thanks, Yeoman. I look forward to reading your work, especially what you have to say on the bust percentages. Were you able to come up with a way to quantitatively determine those for each level of experience? Or is it more of an estimation? Either way, sounds interesting. I'm sure your data on experience is better than mine if you've pulled it from team websites. I was kinda going for the path of least resistance there. I might hit you up for that to use for part two of this study.
It's not even an estimation, it's something reshp pulled out of his hat and I just went with what he proposed because...well, because it was his idea in the first place and i didn't have anything better to offer. It doesn't seem all that sensitive to the details and I thought the idea was sound.
I don't think it's going to add much to what you're already doing here, so what I think I'm going to do is try to link the spreadsheet with the raw data, and then anyone that wants to can play around and look for signals in the noise, run regressions on other offensive stats or whatever. It'll be easy to play with the lookup tables if anyone wants to do a sensitivity analysis on reshp's values.
Just want to say this is really really valuable work. It teases out a lot of the arguments here from both sides of several issues (interior vs tackles, average vs weakest link, etc) that weren't previously based on much data.
One other thing that needs to be addressed: Michigan would have had one of the best offensive lines in the country in regards to experience last year. So, what was up with the subpar performance from the tailbacks and everyone who wasn't Denard? The fact that only Denard could make a thing happen on the ground makes it quite clear to me that despite the youth excuse, Michigan's OL coaching has been dismal.
Getting some time depth on this study would be worthwhile, and it's something I might look at in the future. You're right, of course, that Michigan had a very experienced line last year, and that the RB production was pretty grim. This is why I tried to be pretty guarded with my conclusions regarding the indictment/absolvement of the coaching staff. Even though we fall pretty close to the trend line in terms of YPC once experience is accounted for, I still think there must be problems on the coaching side of things. It's a big data set, and there are definitely experienced teams that suck at running and young teams that are quite good at it, and this variance could be due to any number of things (e.g., RB skill, scheme, O-Line talent) in addition to player development. If we looked at the data over the course of the Hoke/Borges/Funk tenure, we'd have a better idea of whether we're consistently underperforming given our experience.
Considering this great analysis, what if the offensive linemen who give Michigan the "best chance to win" in 2014 are Magnuson (LT), Bosch (LG), Kugler (C), Kalis (RG) and Braden (RT)? Shoiuld they just go with that lineup, live with what might be another disastrous season or two for the offense, and then hope that by the 2016 season, Michigan will have a pretty good rushing attack?
But you (and anyone else looking at this in their own way) need to look at the age and experience of the entire position group, backups included.
When Kyle Kalis beats out other 1st and 2nd year players, it's not nearly as significant as when Steve Hutchinson beats out two or three 4-star upper-classmen. Greg Skrepanek starting as a true freshman was way more impressive than Bosch (not claiming that Skrep was a better player).
Even if the data here represents independent observations, which it does not, the correlation coefficient for "interior linemen" demonstrated in the analysis is 0.22. So, there is a ton of the variability in YPC not explained by age, snaps, starts or whatever experience. Tell Auburn they are too young to run block, go ahead.
This is fun, but in reality teams win when they make the best of the talent they have. I am confident that Michigan will be better, one day, than they are now. But simply starting youngsters and expecting them to perform better next year without coaching and conditioning is probably a mistake. I have this opinion that (a) line blocking is harder than most people think and (2) any player not in the winter condtioning and spring ball programs, especially linemen, will be at a huge disadvantage. So, there may be a bigger difference between Frosh and Sophmores than there is between Juniors and Seniors. The relationship is not necessarily linear at the individual level. We are dealing with individuals and one team.
Auburn is young in years but Alabama was young in starts. I just noticed they flipped but I don't know how many others have juniors that have never played before this year.
With more data we our look at other things like prostyle vs spread offense. An interesting dummy variable could be conference as well. That is a lot more data to collect though.
That's a good point, and I think it's the type of info I should be able to get without too much work. What measure of experience do you think would work best for each position along the o-line? Total or average of the two-deep experience at each position? Or do you think the best measure might just be the most experienced person on the 2-deep at each position?
For example, let's say we've got Bosch (true freshman = 1.0) as the starter at LG and Bryant (RS sophomore = 2.5) as the backup. Do you think a total (3.5) or average (1.75) (these are essentially the same measure) would would work better than either taking the experience of just the starter (Bosch = 1.0) or just the most experienced person (Bryant = 2.5)?
The more I'm thinking about it, the more I'm thinking the most experienced person on the two-deep should serve as the experience measure for that position. You don't want lower Michigan's experience metric at LT or RT just because they've got young backups, which would happen if you take a total or average. But you're right that younger guys should get some type of credit for beating out a more experienced teammate.
Guys are able to play all positions along the line, as evidenced by trying Braden out at guard, moving Glasgow from guard to center, and Magnuson from tackle to guard.
I would compare the sum of years in the program, the sum of starts, and the sum of star-rating.
Instead of weakest link, i'd be interested in a "harmonic mean", which is a type of average that favors the smaller elements. It's like weakest link but doesn't go all the way, and it better seperate out teams with two inexperienced players versus 1.
The other thing would be to include the information about available seniors/juniors. If there was high attrition then that might cause the o-line to suffer significantly.
This is what I love in a diary.
I love this! If everyone on this site read this, it would alleviate some of the PANIC! I'm not a math guy, but I can tell you as a football coach that when you have young players on the line, it has disasterous effects. We are witnessing it now.
Nice to see that an (in)experienced interior is actually more indicative of a quality line than having great tackles. This goes contrary to what most football fans believ: that a pair of good tackles= good O-Line.
it is not PANIC. It is rushing for -49 yards against MSU, and then -21 yards against NEB... who had not kept any other team under 200 yards. This goes WAY BEYOND youth/inexperience.
And the fact that it is getting much worse as the season has progressed is even more indictment against the coaches. We are getting much worse even though our experience is growing (significantly for our interior OL). Also, because other teams can see what we do/don't do and game plan to murder us. Which they do because our coaching hasn't allowed a gameplan to be chosen that gives us counters to what defenses will do against us.
This is REALLY, MOSTLY on the coaches. No other way around it.
And yes, we are young, and yes, this does hurt us.
But it is the coaching in many different facets.
I do agree with you, partially.
I have never been a Funk supporter. I have always thought that a coach who can't teach a simple concept like Power (a play that a high school team can install in a day and run effectively) is not a good OL coach. I just can't understand why we can't down block and pull effectively to make it work. I can teach a HS OL to do it in a day, even against blitzes. If you have any semblance of OL rules you can make power work. I think part of the problem, which Brian attests to, is lack of running-game identity, but I don't think it's 100% the problem.
I do have to say that the OL problems on pass protections is a more complex and understandable issue. I do buy that our young interior is going to have major issues with this aspect, which really hurts our passing game.
I do believe the run game is a product of bad coaching, but the pass protection is a youth problem. When you don't have a pass game you don't have a college level offense.
One, do we see a significant improvement next year or do we have to wait until 2015? And two, if our tackles are our best lineman, and guards and the center are much more indicative of how well we can run the ball, and we really wanna run the ball...why not make our tackles guards and put Mags and Braden at tackle? Heck Schofield already has played guard in the past. I know making Lewan play guard is not exactly an easy sell, but if you're a Michigan Man and it's best for the team, why not? Does this sound at all feasible?
Does it further matter whether your weakest link is your center?
Actually it looks like it does. A brief crunch of the data shows that when the center is the youngest on the interior line (n=23), teams average 4.1 YPC. When a guard is the youngest on the interior (n=77), teams average 4.4 YPC. Oddly, when both the center and a guard are the youngest (i.e., the same amount of experience) (n=25), teams average 4.7 YPC.
This is supported when you look at how well each position serves as a predictor of running success. The center spot has a correlation coefficient of 0.20, an r-squared of 0.04, and p-value of 0.02. When you use the youngest guard as a predictor, you get a coefficient of 0.14, an r-squared of 0.02, and a p-value of 0.11.
Probably could look at this a bit more, but preliminary returns show that yeah, center appears to be the most important.
didn't read all the comments, but I'd like to see your exact same stats but only include RB YPC - UM would be much worse and this would highlight just how f'd-up our running game is. And with this information, we can more justifiably say that Borges needs to get on the wagon out of town. It is just 100% not acceptable.
But good post - great info and graphs.
+1 to the OP.
The thought of those numbers is sobering if also depressing.