Playbook Confidential : Yards-Per-Play Charts

We're going to take a break from the usual weekly offensive breakdown and steal an analysis method from SBN sister site Silver Screen and Roll. Dexter Fishmore likes to look at Points per Possession charts like this, of the Lakers offense in NBA competition (here's the Clippers version from the same game).

It hit me that this would translate quite nicely into a Yards-Per-Play chart for football. I used the same method of charting actual per-play results, and then adding in a rolling 7 play average (this includes the three plays before and after each snap). I'm going to post the chart for the last two Charger games - vs the Chiefs and at the Browns. See if you can guess which chart was the win, and which was the loss.

Chart A

Chart B

If you guessed Chart B was the win vs the Chiefs, and Chart A was the loss at the Browns, you guessed correctly! The offense against the Browns had fewer big plays, more negative plays, more zero plays (read: incompletions), and a much lower average line as opposed to the game against the Chiefs (4.1 YPP to 7.9 YPP).

The creepy thing is they both follow a somewhat similar path through the flow of each game. Both chart averages show:

- A fairly decent big bang to open (this is the pre-adjustment, scripted portion of the offense)

- Then the flow of both games comes down sharply from about halfway through the 1st quarter until halfway through the 2nd quarter.

- Rather nifty two-minute drill field goal drives to end of each half

- Halftime offense adjustments that seem to have gone badly, as the rolling average struggles at the start of the 3rd.

- Then then both have mild success between the late 3rd and early 4th before slamming into a wall to end the game.

So there you have it, two games with vastly different offensive production, but eerily similar game flow.

Next Opponent

Despite the win and Philip Rivers' passing efficiency, the San Diego Offense DVOA took a dip down this week. They are now the #26 ranked offense in DVOA. That's only five spots from the bottom. This offense is statistically bad. The passing offense continues it's season long slight edge on the running game.

The Tamba Bay defense is quite the statistical oddity. In pure yardage terms, they are the absolute best rushing defense in the league, and the worst passing defense. Their DVOA numbers bear out the same general balance, but drop the rushing defense one rank to #2 and pull the passing defense up to average at #17. Turner will have to put this game on the shoulders of Rivers. Mathews will not be able to maintain his decent YPC he's been carrying thus far. The Bucs defend WR1 and TE's decently in the passing game, so look for the Chargers passing attack to continue to hit Ryan Mathews and Ronnie Brown out of the backfield while the non Malcom Floyd receivers will need to show up.

Keep in mind that for defense DVOA, negative is good, while negative is bad for offense DVOA. All VOA, DVOA, YAR and DYAR statistical values are developed, calculated and reported by Football Outsiders. Their explanation can be found here.

A Playbook Confidential intro can be found here.

The cumulative 2012 Chargers play calling log can be found here.