Hennegraphs (Take 2)

Submitted by Swayze Howell Sheen on October 17th, 2009 at 7:27 AM

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.




Threet '08:




































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.

Comments

thevictors85

October 17th, 2009 at 10:14 AM ^

awesome job! looks great... thanks!

[edit] - im curious how henne's grap would look for the cap one bowl, and, while we're on the topic of chad henne, his MNF performance too...

Seth

October 17th, 2009 at 5:13 PM ^

Things that stand out:

1. Tate has very very few IN's, even compared to Henne. I have a feeling the BRs will diminish when he's not as much of a freshman.

2. Look at all the INs for Henne when he was injured in '07. Imagine half of those as CA's with a working arm and that ends up a good year for Michigan.

3. The TAs have gone way up. That's obviously the offense, which has the QB run more often (especially Tate). Any thoughts on adding "RA" (run-aways) as, say, a green to show the positive effect of like a 6- to 20-yard run downfield?

bliang

October 18th, 2009 at 8:50 PM ^

Semi-related, do you think DSR is a good candidate in simple horizontal spark-line presentations?

There probably needs to be more negative modifiers to show bigger swings (i.e. DSR-w/BR_normalization), especially if the goal is to differentiate between several QBs over the course of a season.

WolverBean

October 19th, 2009 at 2:27 AM ^

I think what strikes me most about this is how much detail Brian is putting into the UFR's now. There are 10 different categories for possible outcomes represented in this year's Iowa game breakdown. The visual representation really emphasizes just how much information the UFRs contain.

Two suggestions:
1. While "Downfield Success Rate" definitely makes most sense as a percentage, I think the other measures are actually more revealing on a per-attempt basis, rather than as percentages. I think the game-to-game comparisons would become more meaningful that way, since the total number of passes thrown varies considerably from game to game.
2. (this is really nitpicky) could you reverse the x axis? My natural instinct is to see positive events to the right and negative to the left.

But feel free, doing such beautiful work, to completely disregard my peanut-gallery suggestions. +1.

mvp

October 19th, 2009 at 3:12 PM ^

...for this response and the original post. 100% agree that Brian's analysis of the game is *way* beyond what anyone is getting anywhere from the MSM. I especially like that he tries new things and actually looks for constructive criticism.

The nitpick engineer that resides somewhere in my past agrees with point #2. More importantly, though, the point in #1 is spot on. Actual numbers are better than percentages here.

Also agree with the other poster that asked to see the bowl game against Florida.