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Cal football, Evans Hall edition: Intro to College Football Advanced Stats

Football is a data heavy sport, although it may not be as data driven as baseball, it still has some very interesting nuggets for us to discover! In this and upcoming columns I will be taking in a closer look at Football Outsiders,, and data. In this installment I will be looking at the advanced stats for the 2014 season.

Brian Bahr/Getty Images

First and foremost: hello again!

My name is Piotr and I will be writing the weekly posts on how the Cal football season is shaping up from an advanced statistical standpoint. Quick intro about me: Cal '14 grad in Economics and Political Economies and now I am studying at the McCourt School of Public Policy at Georgetown. I am a novice to the sport and to the field of advanced sports statistics, however, I am willing to learn and share what I have learned with you all!

Without further ado, let us begin!

One of the big and current names in the field of football statistics is Bill Connelly who writes for both the SB Nation's Football Study Hall and Football Outsiders. His team's main contribution to the field of collegiate football are the FEI (Fremeau Efficiency Index) and the S&P+ (Opponent Adjusted Success Rate & Equivalent Points Per Play). Both of which have detailed subcomponents and weights that assigned to these subcomponents. All of it in the pursuit of a more advanced way of approaching and looking at data that extends beyond the box-score.

Sure, we can see who won by applying the age ol' method of "If you wanna win, you gotta score more points than the other team." However, how well did the team perform? Are we meeting our expectations? How can we predict the next match-up? How does our team stack-up without having to rely upon the wisdom of the "eye-test" and of arm-chair quarterbacks?

These questions are hard to answer, especially in football, because like life it is not all math. We can boil down each play and movement into numbers and equations, but ultimately we will still arrive quite short of the desired outcome.

First let's delve into what are FEI and S&P+?

FEI is a measure of the team's ability to efficiently move the ball down the field. This measure is measured on a per-drive basis. This statistic, after eliminating end of game kneel downs etc., tries to measure how well a team is performing on offense, defense and special teams relative to the teams they are facing.

S&P+ consists of 5 different ideas that Bill Connelly and others believe impact a team's W-L record. Those ideas are:

  1. efficiency,
  2. explosiveness,
  3. field position,
  4. finishing drives,
  5. and turnovers.

This statistic, unlike FEI is calculated on a per-play basis. The first two ideas I consider as the most important. As Connelly stated in his book ""Study Hall", explosiveness of an offense is the variable with the most correlation with winning. Explosiveness is defined by big, SportCenter-esque, plays that rouse the hearts and minds of fans. (Such as this). Explosiveness rating is also dependent on the field-position, it is a whole lotta harder to make big plays on the opponent's 30 yard line since the field is getting more compressed. To account for the compression of the field, the expected point value of the field position is taken into account. (Cal Econ Professor David Romer also did the calculation for his paper on Firm Profit Maximization).

While as efficiency discusses the meat and potatoes of a drive: the ground up, get the 5 yards on the first down plays. Overall, the methodology of calculating the efficiency is quite simple and it is defined as "Did the team gain:

  • 50% of the needed yards on 1st down.
  • 70% of the needed yards on 2nd down.
  • and 100% of the needed yards on 3rd down.
The thinking behind this is to show that even with a high rate of explosive plays, it ain't nothing if we can't also convert the basic yards and plays in between. Not every play needs the dragon to be unleashed (unless the QB is Sexy Rexy, then you always unleash the dragon). Taking this into consideration, we can begin to bring together the ideas of what makes an offense efficient. These metrics can also be flipped for the defense: Can they stop big plays? Can they force the offense to make inefficient plays?

One of the core ideas behind these statistic, is the fact that these statistics are opponent adjusted, thus try to account for the difficulty of the team. This addresses the issue with measuring offenses, defenses, and special teams by using yards or even points scored. This allows us to address the discrepancies between the schedules of each teams. Of course, these statistics do not account for the types of offenses the teams face and other factors such as weather, injuries etc.

How do these relate to Cal Football?

If we look into Cal's 2014 Season we can see both very encouraging signs as well as flashbacks towards despair.

First, let's look at the FEI and S&P+

FEI 61
S&P+ 65

(Source: FEI and S&P+ Data) PS. I will not be delving into the F/+ stat just yet.

These numbers put us right, smack dab, in the middle of the FBS pack. Which would prompt you to say: "Wait, what about our Goffense? How bad was our Defense to put is in the middle?

Let's see!

Offense Defense
FEI 32 85
S&P+ 30 97

(Source: S&P+ Offensive for 2014)

(Source: FEI Offensive for 2014)

As we can see, Cal doesn't have a problem with producing explosive plays, and being efficient on offense as you may recall. This also will not be a huge worry for us in 2015 since we're returning nearly all of our offensive production, top playmakers, all with another year in the system. However, as you can see and recall, we do have a problem defending large passing plays, if we look at the defense's performance in the BYU game from last year:

Type of Touchdown Yards Explosive?
Rushing 1 No
Passing 47 Yes
Passing 22 Yes
Passing 9 No
Passing 83 Yes
Passing 38 Yes

(Source: Sports Reference)

This is a very small and narrow sample size, but it highlights the fact that, if our safeties and corners need to not get burned by explosive plays. If we look at the detailed S&P+ ratings for defense:

Rushing Passing
S&P+ 56 115

(Source: S&P+ Defensive for 2014)

We can it is quite evident that it is our Passing Defense that is showing a huge liability to the team. Of course, everyone who saw Cal's performance can state the same thing as these fancy statistics. What matters, however, is the ability to compare between the teams. It allows us to go beyond the "eye-test" and actually begin understand just "how bad/good" a team is at the current moment.

Of course, football is anything but a game of numbers. The football doesn't care about FEI, and S&P+ rankings, nor does it care about yards gained or loss. And that is why we get successful Hail Mary's against our own team, but also 19 yard missed field goals for us.

What's next Mrs. Landingham?

Next, week as a pre-view for the upcoming season I will look into the slate of opponents Cal will face in the upcoming season from the same standpoint as I did Cal for this article. Of course I am open all feedback!