Improvement, Quantified

Submitted by ikestoys on

[Ed.: as a basis for discussion. IME, the FO-based stats are the best available for reducing noise when you're evaluating how good of a team you've got.]

Hey guys, I don't know about you, but 99% of the conversations I've seen or heard about Rich Rodriguez's future at the University of Michigan hinge on how much each person thinks the team has improved. So obviously, the question is how much have we improved, exactly?

To start off, I'm going to make a few assumptions and attempt to defend them. First, very few people can simply watch the games, watch the highlights and determine if their own team has gotten better. Frankly, we don't know enough about the game on a micro level for our eyeball test to mean anything, not to mention the TV angles don't have large parts of the play, we don't know what play was called, etc.

Secondly, no mere mortal is actually capable of rating teams, especially the mediocre ones. There are around 50 games a week during the season, and while many of us wish we could be superfans, we simply are not capable of watching that many games in any meaningful sense. If you aren't watching the games, what are you basing your eyeball rankings off of?

Because of those two assumptions, the only place we can really look for improvement is found in statistics.

Statistics? @#$@, like math?

Yeah, sorry

Don't they lie or something?

Well, yeah sometimes. There are many different ways to look at football statistically, and frankly, all of them have fairly severe flaws. Football simply has too many intangibles to model mathematically as well as baseball. However, that doesn't mean that all statistical analysis of football is useless, just that you have to be careful not to overstate your case and to look at the data in as many ways as possible. For this diary, we're going to look at three major ways of quantifying football games. The goal is to compare the results and see if we can get some sort of idea of what's going on.

OK so what are these different ways? Didn't Brian post about FEI or something?

The first, and most common, are methods that mostly rely on looking at  who won against who and/or by how much. This is the type of method used by Sagarin, Massey and more. For the BCS formulations, Massey and Sagarin are not allowed to use margin of victory in their calculations. However, when Massey and Sagarin use margin of victory, their models are more accurate.

The second one we'll look at is basically drive analysis. This is FEI, and is best explained by Football Outsiders:

The Fremeau Efficiency Index (FEI) considers each of the nearly 20,000 possessions every season in major college football. All drives are filtered to eliminate first-half clock-kills and end-of-game garbage drives and scores. A scoring rate analysis of the remaining possessions then determines the baseline possession efficiency expectations against which each team is measured. A team is rewarded for playing well against good teams, win or lose, and is punished more severely for playing poorly against bad teams than it is rewarded for playing well against bad teams.

The last one we'll look at is an analysis that uses a play by play analysis. Again, Football Outsiders:

The S&P+ Ratings are a college football ratings system derived from the play-by-play data of all 800+ of a season's FBS college football games (and 140,000+ plays). There are three key components to the S&P+:

  • Success Rate: A common Football Outsiders tool used to measure efficiency by determining whether every play of a given game was successful or not. The terms of success in college football: 50 percent of necessary yardage on first down, 70 percent on second down, and 100 percent on third and fourth down.
  • EqPts Per Play (PPP): An explosiveness measure derived from determining the point value of every yard line (based on the expected number of points an offense could expect to score from that yard line) and, therefore, every play of a given game.
  • Opponent adjustments: Success Rate and PPP combine to form S&P, an OPS-like measure for football. Then eachteam's S&P output for a given category (Rushing/Passing on either Standard Downs or Passing Downs) is compared to the expected output based upon their opponents and their opponents' opponents. This is a schedule-based adjustment designed to reward tougher schedules and punish weaker ones.

The S&P+ figures used in the tables below only look at the plays that took place while a game was deemed "close," or competitive. The criteria for being "close" are as follows: a game within 24 points in the first quarter, with 21 points in the second quarter, and within 16 points in the second half.

OMG Wall of Text! I'm Lost!

Think of it this way, we're looking at the game at three levels: final scores, drives, and plays.

OK that sounds more reasonable. Results?

Remember that a lower ranking is better. The average improvement from 2008 is about 48 places (from 89th to 41st) . Sagarin's BCS formula has the most improvement at 71. FEI (Drive analysis) is the smallest at 31 places.

So what the hell does that mean?

It means that Michigan improved a lot. In 2008, Michigan was ranked in between 68th and 105th. In 2010, Michigan was ranked in between 30th and 53rd. That is a huge leap.

The drive analysis and play by play metrics show the least amount of improvement for Michigan, however, those rankings had Michigan much higher in 2008 than the win/loss metrics.

Now, it's up to you exactly if it's enough to keep Rodriguez, but hopefully now you have a better idea of exactly how much that improvement was. 

Go blue!

Comments

nazooq

December 1st, 2010 at 12:06 PM ^

It will take much more than a year of maturation.  Stanford cleaned house on the defensive side of the ball after 2009, retaining only their recruiting coordinator, Lance Anderson, who shares linebacker coaching duties.  All their other defense coaches are new, led by a highly accomplished NFL coordinator, Vic Fangio and new secondary and defensive line coaches.  Will Rodriguez have the guts to demote or fire his friends?

MGoShtoink

December 1st, 2010 at 8:44 AM ^

These charts are basically used to show improvement or decline by the two coaches, correct?

If that's the case, then the X-axis needs to be done by Year 0, Year 1, Year 2, Year 3... etc.  Showing them by calendar year leads a less knowledgeable person (i.e. one who doesn't know Harbaugh has had an extra year) to think that they can be directly compared year by year.

If you don't want to do that, then look where the offenses are.  We have a "better" (higher rated) offense in just 3 years.  The improvement from Year 2-Year 3 for RR is huge and that's with a very young team!

That said, look at the potential upswing we are facing next year.  We'll have more mature team, T-Woolf and the rest of the injured reserves will be back.  We may just be poised to see the same dramatic upswing.  Plus, we are at the bottom of the barrel now, so the only direction to go is up (which is where the 2010 Stanford team went in dramatic fashion).

SmithersJoe

December 1st, 2010 at 10:36 AM ^

X Axis normalized so that Year 1 for Michigan = 2008, Year 1 for Stanford = 2007

And just to highlight the fallacy of the assumptions being made with these charts, here is the linear extrapolation of Michigan's progress for next year, compared to the FEI of Stanford this year.

Following this nonsense to its logical conclusion, we can say that Michigan under Rich Rodriguez after 4 years still won't even be as good as Stanford under Jim Harbaugh after 3 years, much less 4 years.

Oh, and by the way, the FEI data for 2010 doesn't include last week's game, Michigan v. Ohio State (7-37) and Stanford v. Oregon State (38-0).

SmithersJoe

December 1st, 2010 at 12:08 PM ^

"Let's me explain.  No, there is too much, let me sum up."

The extrapolation is what people are implicitly arguing with this data.  "Look how much we've improved over the past 3 years!" (therefore, we will continue to improve at a similar rate next year and in future years, and it's only a matter of time before we get the quality of program that we want...)

By making that extrapolation explicit (ie "drawing a line on a chart"), I'm trying to highlight the fallacy of this nonsensical argument.

DustomaticGXC

December 1st, 2010 at 2:18 PM ^

to convince me the team will be better next year.  All I have to do is look at the number of returning starters on both sides of the ball, look at the number of players who will be returning from injuries, and have half a brain.

 

And I don't need numbers to tell me the team is better than it was last year or the year before, because I have eyes and a memory.

SmithersJoe

December 1st, 2010 at 2:51 PM ^

Your prediction of future improvement is a fair, subjective opinion based on your personal perception of what causes improvement.  You are convinced, but that's all it is - your belief.  That's fine, that's fair, and I don't have a problem with people who express opinions as opinions.

The OP, and most of the comments attached to it, are trying to predict that improvement next year will be an objective, statistical fact.  That is what I am trying to debunk.

Blue_n_Aww

December 1st, 2010 at 9:17 PM ^

The OP, and most of the comments attached to it, are trying to predict that improvement next year will be an objective, statistical fact.  That is what I am trying to debunk.

 

Where did OP predict improvement? Isn't the post trying to show improvement over the past three years? Isn't the question posed, "How much has the team improved, exactly?" Note the verb tense.

SmithersJoe

December 1st, 2010 at 9:38 PM ^

ikestoys:

Hey guys, I don't know about you, but 99% of the conversations I've seen or heard about Rich Rodriguez's future at the University of Michigan hinge on how much each person thinks the team has improved.

smithersjoe:

The extrapolation is what people are implicitly arguing with this data.  "Look how much we've improved over the past 3 years!" (therefore, we will continue to improve at a similar rate next year and in future years, and it's only a matter of time before we get the quality of program that we want...)

Why this OP if not to imply that Michigan under Rich Rodriguez will follow this "improvement trend" next year?  To argue that the OP is not implicitly attempting to get people to extrapolate from this data is disingenuous, at best.  Just look at the resulting comments - people extrapolating from this data.

Consider the position you are defending - the OP is suggesting that Michigan should choose to retain or fire Rich Rodriguez based solely on past accomplishment, without extrapolating for future performance.  If so, then the OP would be framed in terms of 3 year averages, not 3 year trends.  The whole purpose of showing this data as trends is to induce people to extrapolate.

What is the point of looking at improvement (used 7 times by OP) if not to extrapolate for future performance?

Blue_n_Aww

December 2nd, 2010 at 1:00 AM ^

Because that's what Dave Brandon is looking at? I think you can look at the efficiency numbers in conjunction with our roster in addition to the product on the field and conclude that it's very likely that we will improve those numbers next year. And, in turn, win more games, of course. 

I'm not really sure what you're driving at to be honest; you're certainly obfuscating any conclusion that you're trying to make. What do you mean by "averages"? What would you like OP to average? Are you suggesting that he should present a unified view of Rodriguez's tenure? I think that's ludicris if that's what you're arguing. Dave Brandon has said repeatedly that he's looking for improvement in the program. And here is improvment.

I've seen many on this board argue that we haven't improved from last year, and so I don't think it's disingenuous in the slightest to provide evidence that refutes that point of view.

SmithersJoe

December 2nd, 2010 at 9:19 AM ^

I don't disagree that there has been "improvement" over the past 3 years.  I don't disagree that people can have their opinion about whether there is likely to be improvement next year.  I do disagree with how people have been trying to use data like this to imply that improvement next year is a statistical probability (much less a certainty).

Think about it this way.  I noted in one of my earlier posts that the average change in FEI ranking (indeed, for FEI score itself) for all teams is zero.  That means there are teams that increase in a performance metric like FEI from year to year, and there are teams that decrease in the same performance metric.  In fact, the average of all of those increases and decreases, from year-to-year for all teams, is zero.  From a purely statistical perspective, it is no more or less probable that Michigan will increase or decrease in FEI score / ranking next year.

One should not use data like this to project into future performance, especially not in a linear way (like I tried to demonstrate with my sarcastic "let's draw a straight line!!!!" chart).

One can certainly talk about past performance in terms of numerical data, but extrapolating that data to future performance is not, in my view, legitimate for something like football.  Population demographics, disease epidemiology, the number of transistors that can fit onto a silicon chip - those are all systems that have reasonable, mathematical models to justify the use of extrapolation.  Football does not.  The intangibles and subjective opinions - about youth, about injuries, about incoming recruits - those are all fair things to speculate about and base our opinions upon.  But don't fool yourself into thinking that we have any statistical certainty about this stuff.

Most of the arguments I've heard about whether to retain or fire Rich Rodriguez are not based on actual performance - they are based on projections into future performance.  That's fine - project all you want with your subjective opinions.  But don't misuse data to imply that future performance is somehow statistically guaranteed to improve.

Also, I apologize if my satirical style is obfuscating my point.  By generating "lots of chartzzz" and drawing ridiculous conclusions from them, I'm trying to point out the inherent fallacy of using data this way.

SmithersJoe

December 1st, 2010 at 11:57 AM ^

Ignoring the absurdity of using ordinal data to draw conclusions about trends, here is the change in FEI rankings from 2009 to 2010 for Michigan, Stanford, Big 10 average, and Pac 10 average. Of course, the overall average change in ranking is 0.

This chart lets us draw the ridiculous conclusion that defensive improvement from Year 3 to Year 4 of a coach's regime is extraordinarily better than the average improvement on defense in a year for the Big 10, Pac 10, and overall.  What if we completely bastardize the statistics and look at change in FEI scores from 2009-2010?

Now let's look at the combination of Defensive and Offensive change in FEI scores.

Hey - Michigan actually improved more overall than Stanford did, and more than the Big 10 or Pac 10 average!  All we need is the 3rd Year to 4th Year bump in defensive improvement, not even as much overall improvement as this year, and we'll be better than Stanford!  What's better than 11-1?  12-0 baby, National Championship, here we come!

"Inconceivable!"

"You keep using these numbers.  I do not think it means what you think it means."

Eye of the Tiger

December 1st, 2010 at 10:05 PM ^

Stanford is 4 wins better than us because their offense is almost as good as ours and their defense is leaps and bounds better. Now that comes from much more than just the HC (injuries, positional coaches, freshmen starters, etc.), but let's just admit it: They are better than us this year, and were better than us last year. Does anyone really think we'd win that matchup? I'd give us about the same chance we had against Wisconsin.

Yard Dog

December 1st, 2010 at 8:44 AM ^

He's the one coach who has actually delivered a National Championship in the last 60 years, and people are accusing him of screwing the program on the way out the door.  Does anyone truly believe this?  Lloyd, while not my favorite M coach of all time, did a damn fine job for our school.

This constant Lloyd bashing meme is worse than political discussions of who is right and who is wrong.  How long can you hammer the previous administration for the current one's woes?

While I always enjoy reviewing these statistical analyses, I'm more of a bottom line guy.  6-18 in the Big Ten the last three years while getting owned by the top half of the league is a poor performance regardless of any other statistics.  The question remains:  is this something that you believe will improve enough over the next year to keep RR?  I just don't know.  I'll leave that to DB and trust his judgment.

upnorthinblue

December 1st, 2010 at 9:09 AM ^

 

Well I agree that placing blame for our current coach’s problems solely on Lloyd Carr is not how we should act but facts are facts.  You need top notch athletes year in and year out to be good.  Could Coach Rod have done some things better as far as fitting what he had in his players to scheme? Maybe, but I don’t see that team winning more then 5 games reason being the team is bad and the big ten was  very competitive. The players Coach Rod inherited were not top notch athletes. We cannot be blinded to the fact that we would never have been good regardless the coach the year after Coach Carr left. The athletes were not there.

UM Fan NY

December 1st, 2010 at 10:51 AM ^

no one can argue we're light years ahead of '08 offensively but there was no where to go but up. howeva, there are 3 aspects to football...offense, defense and special teams. we've regressed significantly in two of those areas. that, to me, is not improvement overall. we're improved over last year because we beat purdue and illinois??? that's the difference. we beat illinois on the last play of the game and we beat a purdue team so rocked with injuries that they resemble a pop warner team.  the outcomes of iowa, msu, osu, psu and wisconsin were similar or worse than last year. this is not enough to keep him as coach. just my opinion.

SmithersJoe

December 1st, 2010 at 12:04 PM ^

Yeah, but obviously, the offensive improvement so totally way overwhelms the defensive decline!  The change in the FEI score on offense is 0.816, and the decline in defense is only -0.262.  The overall improvement is clearly positive, and better than Stanford, the Big 10 average, and the Pac 10 average (see my post below for the chartz!!!!!).\

This PROVES we will DEFINITELY win a NATIONAL CHAMPIONSHIP next year!  All we have to do is draw some lines, and Michigan wins!

/s (for the sarcasm-impaired)

Blue in Seattle

December 1st, 2010 at 12:15 PM ^

the point of the original post was to use a strong statistical model to demonstrate improvement.  Unless you think FEI is total crap, then you have to agree that there is improvement.  What the poster then asked was for everyone to state whether this improvments was "enough", and I believe the next step after that to have an intelligent argument is to provide a description of not only what "enough" is, but how you think it can be achieved.

Some have looked at the individual components of the Offensive and Defensive FEI and found that Michigan is #1 on the Offensive ranking, and #103 on the Defensive.  I agree, when the offense was bad it "had no where to go but up".  Now the Defense is bad with "no where to go but up".  Keeping Rich Rodriguez will maintain, or even slightly improve the Offense.

So what do you believe will improve the defense.  I think just growing up another year will do it.  Some think a new DC is required.  Nothing in the data tells me that hiring a new head coach with a new staff and a new playbook will result in overall improvement next year.

Maybe there are problems on the Defensive Staff that must be improved by replacing some coaches.  As far as I can tell, these last two tough games really seemed like players were frequenlty in the correct posistions to make a play, and yet did not.  I attirubte that to mostly their youth and lack of body mass and strength in comparison to people who have spent 4 years in a College Program.  Possibly it's basica technique, but how does an entire Defensive staff, who seem to put the players in the right spots not know how to teach technique?

It seems much more likely that these new players, who have developing bodies, are having a hard time picking up technique right out of high school, especially when some have traded positions throughout the year because of injury, or just the coaches trying to make anything work this year.

yes, all subjective judgement used in a logical way, but it's added to the fact that our defense has no where to go but up and almost everyone is returning! 

 

SmithersJoe

December 1st, 2010 at 12:39 PM ^

Let's start a list of all the fallacies we commit when using data the way we are trying to here.

1. Past performance extrapolates to future performance (ie offensive improvement).

2. Past performance does not extrapolate to future performance (ie defensive decline).

3. Teams play at their "level" consistenly from week to week (ie the Iowa team that played Michigan State performed at the same level as the Iowa team that played Minnesota).

4. Each team is exactly the same team from week to week (ie Michigan in week 13 is the same roster, the same playbook, the same performance capacity as the Michigan in week 1).

5. Teams with higher performance scores (FEI, S&P, whatever) will beat teams with lower scores (ie all Michigan needs to do is improve its FEI score to be higher than OSU's FEI score, and Michigan will beat OSU, just like Iowa beat Minnesota).

6. All other teams performance levels will remain constant from year to year (ie Michigan only needs to improve by x, everyone else stays the same, Michigan wins).

7. Changes in performance scores are completely attributable to the head coach (ie all the improvement on offense is because of Rich Rodriguez).

8. Changes in performance scores are completely attributable to someone other than the head coach (ie all the decline on defense is because of the defensive coordinator).

That's just off the top of my head.  Any others?