Clemson Football and Advanced Stats: Part 2

In part 1 we talked about using a new box score as well as the importance of using rate based stats like yards per carry or yards per completion. Now we are going to delve deeper into the numbers by trying to get a better understanding of the raw data. For those of you who are baseball fans, this is going to be like taking batting average and looking at OBP or OPS and other similar stats. We want to go a step past the basic raw data.

Eliminating Garbage Time

The first thing we are doing with stats is eliminating anything that occurs in garbage time. The idea behind this is that when a game reaches garbage time you see a fundamental change in playcalling. You might even see the backups begin to enter the game. The team that is down is going to begin passing at a crazy rate while the winning team is going to keep the ball on the ground. Because of this we want to remove this data to eliminate any noise in the trends we see. Bill Connelly defines garbage time as being up by 28 points in the first quarter, 24 in the second, 21 in the third, and 16 points in the 4th. Other groups consider garbage time to be anytime when a team is up by more than 21 points or more than 16 points in the 4th quarter. For our analysis this year we will use Bill's definition and then see if any adjustments need to be made.

Line Yards

This is used as an attempt to quantify how much of a team's rushing total is because of the OL versus the RB. Each running play is adjusted as follows; 100% of the total between 0-4 yards, 50% of the total between 5-10 yards, and 0% of the total for 11 yards or greater. If there is a loss of yards then 120% of the loss is taken from the OL total. While not always the case, a loss of yards is often going to be the fault of a missed block or poor blitz pickup, not something necessarily the fault of the RB.

Highlight Yards

Highlight yards are the opposite of Line yards. Highlight yards are designed  to eliminate any contribution from the OL. For this, a RB is assumed to contribute 0% of the rush from 0-4 yards, 50% from 5-10, and 100% for anything above 10 yards. So if a RB has a 15 yard run, he is credited with 7.5 yards of  the rush.

Opportunity Rate

This is the rate at which the OL does its job and allows the ball carrier to rush for at least 5 yards. All that happens here is dividing the number of rushes over 5 yards by the total number of rushes.

Success Rate

One of the most important things in determining if a team will win is efficiency. Not just efficiency in the red zone, but on every single play. The more efficient team per play is the winner over 75% of the time. Efficiency per play is based on the number of yards gained. For 1st down it is gaining 50% of the yards, so usually 5 of 10. On 2nd down it is about gaining at least 70% of the needed yards, and 3rd and 4th down requires gaining 100% of the yards needed. At a bare minimum this success rate will be between 25% and 33%, probably closer to 33% since so few coaches go for it on 4th down.

Power Success Rate

Once again this is a rate that is going to help us determine how our OL is playing. Here we look at the number of 3rd/4th and 2 or less rushes that result in a first down or TD. We've seen problems with Clemson trying to convert on 3rd and short because of poor OL play, now we will get to quantify it.

Stuff Rate

This one we'll look at for both the offense and defense, it is the percentage of rushing plays where the ball carrier is stopped for a loss or no gain. Rather than being a solid number, we want to look at the percentage. 10 tackles for a loss are nice, but a percentage is much better.

Sack Rate

Same as the stuff rate, but it is the percentage of times a passing play results in a sack.

Explosive Drives

These are the types of drives we've seen at Clemson recently. Usually pretty quick, a drive is explosive if it averages over 10 yards per play.

Methodical Drives

One of my favorite methodical drives was Clemson-Auburn in 2011. Clemson got the ball with 8-9 minutes in the 4th quarter and preceded to grind the clock down. I can't remember if it lasted at least 10 plays, but it was great to see. Methodical drives are those that last more than 10 plays.

Value Drives

The last look at drives is going to be for value drives. These are drives that start in Clemson's half of the field and end inside the opponent's 30. The idea being these drives are most likely to result in some sort of score. We'll do some analysis of these drives to see if we are having a problem scoring touchdowns or field goals relative to what we would expect.

Once again I've taken the Clemson - Ohio State game and calculated the above stats for the game. You can see we were a more effective team at moving the ball. Note the difference in sack and stuff rates. We did a much better job at getting into Ohio State's backfield and preventing them from gaining yards.

The success rate number is something I'm very interested in. The only reference we have is between the two teams, but I want to see what the numbers are for other games, see if 55% is good, bad, or something in between.

This isn't going to be all that we look at, and we may drop some of these items as the season goes. If you have any questions, suggestions for what we should look at, or are just interested in more information then let us know in the comments.