For each player, Brian assigns a plus/minus total, and thus, an opportunity for a simple visualization of each player's performance over the course of the year. Ignored for now: the pressure/coverage/tackling metrics. Just player performance, pure and simple.
So, you think this calls for a ... hmm ... graph?
A little explanation. Each game's defensive per-player ratings are shown. For a particular game (say, "Eastern"), each player's plus/minus is shown as a simple bar graph. Blue (to the right) shows a player's positive rating for the game, and Yellow (to the left) shows their negative rating. A single red dot shows the "net" rating for a player for a particular game (i.e., plus - minus); you want these to be right of the center axis! Per Brian's charts (Western, Notre Dame, Eastern, Indiana, MSU, Iowa), the players are grouped into three sets: Defensive Line, Linebackers, and Defensive Backs. Finally, within each grouping, players are ordered by the total number of positive plays they have made on the year (somewhat arbitrarily).
I'm not going to do much/any analysis of the data, but some obvious things do stand out. First (no surprise), Graham is a beast. That MSU performance is ridiculous! Second, the D-Line is a strength of the D and seemingly getting better, which bodes well. Third, linebacker play: ouch. But nice to see Ezeh with a net positive (red dot to the right) in the Iowa game; Stevie Brown has also done reasonably. Finally, D-backs: also some ouch, particularly against ND and Indiana (Cissoko unfortunately a big part of that). Now if we could just get Williams to shore up a bit...
Anyhow, that's it. Not too fancy, but I think a nice way to look at Brian's overall player grading. Now I'm sure you want to give some ... feedback?
(you fill this part in, or not)
Some days ago, I made a first attempt at visualizing some of Brian's famous Hennecharts. After some feedback (thanks all) and some links to old data (thanks Misopogon), I now try again. Here are "Hennegraphs" for Tate so far this year, Threet from '08, and Henne from '07.
and Henne '07:
And finally, Henne in the near-championship year '06:
Some explanations: I took Brian's suggestion to center at 0, pushing "good" events to the left, and "bad" events to the right. Slight adjustment: I moved "Marginal" all the way to the left (it is neither good or bad, but made slightly more sense on the left instead of centered in the middle, as we will see in below).
Recall also that bars that are not fully colored in represent screen passes (which Brian has started accounting for lately).
Also on the Hennegraph: Brian's metric of effectiveness, the Downfield Success Rating (DSR). The Tate '09 graph shows how this is calculated: DSR is the number of (Dead On + Catchable) throws divided by everything else except for Marginal and Pressure. Thus, it is the left blue part (ignoring marginal all the way on the left) divided by the blue part + right red/orange/yellow (ignoring pressure all the way on the right).
I also present the DSR percentage on the right of each bar, as well as the total number of attempts, and graphically depict the DSR number on the left in a dotted red line.
Putting all of this together made me realize the simple genius of what Brian is doing here. Instead of judging a QB by a simple number such as "percentage of passes completed" or some odd QB rating, he is simply analyzing each throw and qualitatively judging them in isolation of whether they were caught or not. Thus, DSR is an excellent replacement for "Completion Percentage" if you are just interested in measuring how well a QB is throwing the ball.
Hope you enjoy. As always, comments are welcome, and thanks to Brian (and Misopogon!) for the grading and the data; any errors, of course, in the Hennegraphs above are mine.