Inside the Numbers: TSL Extra Defensive Player of the Year
by Will Stewart, TechSideline.com
TSL Extra, Issue #19
Last year, for the first time ever, we did a defensive performance calculation and awarded points to defensive players based on their defensive stats. This year, we're back to do it again, and this time, the player with the most points wins the coveted first annual TSL Extra Defensive Player of the Year Award.
The idea of a defensive performance index is simple: award points for certain defensive plays (tackles, sacks, interceptions, etc.), multiply a player's stats by those point awards, and total them up. You can then rank the defensive players by total points, and for a different twist, you can divide their total points by the number of plays they were on the field to get a "points per play" statistic that truly measures a player's productivity.
Last year, it was just a statistical exercise, but this year, we're going to use our formula to name a 2001 TSL Extra Defensive Player of the Year. We're also going to compare this year's stats to last year's.
We need two sets of data: defensive statistics and plays from scrimmage.
1.) Defensive statistics were taken from hokiesportsinfo.com at the following address:
2.) Number of plays from scrimmage and special teams plays were taken from the season-ending depth chart found on page 7 of the December 14, 2001 edition of "hokiesports.com the newspaper" (Vol, 19, No. 15).
Note that statistics are for the regular season only and do not include the Gator Bowl.
Players Included in the Calculation
The defensive statistics posted on the hokiesportsinfo.com web site also include special teams plays and tackles, and that complicates things. I took the list of 50 players that are included in the "defensive stats" and eliminated all of the players who are not on the defensive two-deep roster. This got rid of the special-teamers like Wayne Ward who appear in the defensive statistics because they have made plays on special teams. I also deleted defensive players who did not play more than 100 plays on defense.
I wound up with the following 23 players, all of whom played more than 100 plays on defense in the 2000 season:
DT: David Pugh, Chad Beasley, Derrius Monroe, Channing Reed, Dan Wilkinson
Defensive Plays and the Points Awarded
Here are the points awarded for the defensive plays included in the statistics:
1.) Tackles are complicated, and are calculated like this: when a player makes a tackle, he gets 1 point (assisted tackle) or 2 points (unassisted tackle). If it's a tackle for loss (TFL), he gets an additional 2 points, plus 0.2 points for every yard lost on the play. If the tackle for loss is a quarterback sack, it is calculated just like a TFL, but the player also gets 2 bonus points for the sack.
2.) Points for fumble return yardage are double what is awarded for interception return yardage because fumble recovery statistics typically include less return yardage than interceptions. Most fumbles are recovered on the ground, whereas most interceptions are made standing up with a chance to run. Fumble return yards should therefore be awarded points at a premium over INT return yards.
How Special Teams Skew the Numbers
The fact that special teams plays are included in the defensive statistics provided on hokiesportsinfo.com complicates things and skews the results in many ways. For example:
1.) There are not as many defensive "plays" available to a special teamer as there are to a scrimmage defender -- sacks, QB hurries, interceptions, etc. are not available in a special teams play, except for the rare instances where the opponent runs a trick play.
2.) Sometimes the special team plays are plays like kickoff returns or field goals, where making any type of defensive play is impossible.
This means that a defender who plays a lot of plays on special teams is going to have his point totals dragged down by those special teams plays. On special teams, he can't make a sack or an interception, so on average, he gets fewer points from his special teams plays, no matter how good a special teams player he is.
But on the other hand, the tackles he makes on special teams go into his point totals and help him out, versus a player like defensive end Jim Davis, who only had two plays on special teams all year.
You can sum up the effect of playing on special teams thus:
1.) It increases a player's point totals by giving him more opportunities to make plays, most notably tackles.
2.) It decreases a player's "points per play" figure, because special teams plays don't provide as many opportunities to score points.
I tried to compensate for item number two by dividing the number of special teams plays in half when calculating the "points per play" statistic. So points per play = total points / (scrimmage plays + special teams plays/2). You can argue that I should have divided by a larger number or even thrown the special teams plays out completely, but it was hard to figure out exactly what to do, and that's the step I took.
And Now, the Results
Given all that, let's throw those 23 players and their stats into a spreadsheet and see what comes up. The table that shows each player's statistics and their resulting point totals is too lengthy and cumbersome to print here, but it can be viewed as a web page or a Microsoft Excel spreadsheet (see the end of this article to find out how to download the data).
Players Ranked by Total Points (TSLX Defensive Player of the Year)
This year, for the first time, we'll hand out the TSL Extra Defensive Player of the Year to the player with the most defensive points. Without further ado, here are the top ten point scorers:
* 2001 TSL Extra Defensive Player of the Year
Ben Taylor leads total points for the second year in a row, which makes him a repeat winner (even though we technically didn't hand out the award last year). Last year, he only had 251.2 points, which means that he upped his store by 55 points, even though his overall plays only increased by 18, from 743 last year to 761 this year.
It's not a surprise that the top four spots are held by linebackers and safeties. Both positions can make all of the plays on the field, because they provide run support and pass defense, as well as blitzing to sack the QB.
Linemen and cornerbacks don't have the opportunity to make every defensive play available, because linemen typically don't fall into pass defense (it happens, but it's rare), and cornerbacks rarely blitz and get the opportunity to rack up TFL's, sacks, and QB hurries.
So the top slots are usually garnered by the guys whose responsibilities run the defensive spectrum: linebackers and safeties (including both free safety and Rover).
Players Ranked by Points-Per-Play
And in the all-important points-per-play category, which is another measure of a defender's effectiveness on the field, here's how it shakes out (a score of 0.40 or higher indicates a very productive defensive player):
Things to note:
Comparison to Last Year
As noted, Taylor upped his production from last year by almost 22%, despite only logging 2.4% more plays. Here are some other notable comparisons to last year (see TSL Extra Issue #5 for last year's point totals):
To download the data in HTML (web page) format, go here:
The page at the above address lists the players from first to last in terms of total number of defensive "points" scored.
To download an MS Excel 97 spreadsheet containing all of the data and formulas that I have used here, go here:
I hope the spreadsheet has no significant errors, and I hope you enjoyed yet another brain-bruising installment of "Inside the Numbers"!