Monday, October 02, 2006

A Rough Look At ACC Offensive Tendencies

Let's start here:

Team GamesPlaysPass AttRush AttPass %Rush %Yds/PaYds/RuPlays/G
Clemson 533813120738.861.27.85.867.6
Ga Tech 530512617941.358.76.94.961
NC State 423211212048.351.75.54.258
UNC 423811712149.
Va Tech529914915049.850.28.23.559.8

The above table should be self-explanatory. The Pass% and Rush% columns indicate the proportion of a team's total plays that are pass attempts and rush attempts, respectively. Wake Forest has been the most run-heavy team in the ACC so far, attempting a run on two out of every three plays. I've also included yards per pass and per rush, and it is these two statistics that I'm going to look at more closely.

A couple of quick notes before moving on:

-- Duke is averaging 1 yard per carry, which is about the saddest thing I've ever seen. Virginia isn't much better. The Blue Devils' passing game looks better (per attempt) than UVA's, but as you'll see, it really isn't.

-- Clemson: wow. Very impressive Yds/Pass and Yds/Rush averages. The Tigers haven't been throwing the ball much, but when they do, they do it effectively.

Now that we've perused that first table, let's move on to something a little more interesting. Back in July, Brian discussed a balance/game theory post made on a blog called Smart Football. I'll let Brian explain the gist of the concept:

The idea here is that if your results from the running and passing are out of wack you should be adjusting your run-pass ratio in a counterintuitive fashion because the defense will be expecting you to do what you're good at. If your yards per play for both are approximately equal with the addition of a "passing premium" of about a yard per play, your offense is operating with the correct balance between run and pass: you've reached a Nash equilibrium that balances what your offense is good at with game theory considerations.

Balance in this sense, then, comes when you're getting about a yard more per pass attempt than per rushing attempt. If you're getting, say, 3 yards more per pass attempt than rush attempt, then you need to throw the ball more. Throwing the ball more will force the defense to react, bringing your yards/pass attempt down, but giving you more opportunities on the ground, thus increasing your yards/rush attempt.

Looking at the first table in this post, NC State looks like the most balanced team in the conference, with a +1.3 yard passing differential. That's right where you want to be. There are some pretty large differentials in the table, and it appears as though several teams are running way too much. But are they really?

There is one minor adjustment that needs to be made in order to get a more accurate look at yards/pass and yards/rush. One of the differences between NCAA and NFL rules is that the NCAA negates sack yardage from a team's rushing yardage rather than its passing yardage. A coarse way to account for this is to simply remove all of a team's QB rushes and yardage from the running stats and add them to the passing stats. For example, Carolina's quarterbacks have carried the ball 21 times this season for 58 yards. To adjust, we'd subtract those figures from the team's rushing numbers (giving Carolina 100 rushing attempts on the season, not the 121 seen in the first table) and add them to the team's passing numbers (giving UNC 138 pass attempts rather than 117). This adjustment becomes a problem for teams (like Clemson or Georgia Tech) that have designed QB runs in the playbook, but for my purposes here, I think it's okay.

In the table below are the adjusted running and passing play totals, as well as the adjusted yards/pass attempt and yards/rush attempt. Now, there is a certain school--a school with which you're likely familiar--that isn't like the others. This school, not to name any names, features a lot of red. It has some well-known problems passing the ball. This school purports to be a running team, but it's gotten away from the run this season (partly because of circumstance).

TeamAdj Pass AttAdj Yds/PaAdj Rush AttAdj Yds/Ru
Ga Tech1806.11255.1
Wake Forest1275.71695.1
NC State1354.5975.3
Va Tech1736.81264.5

The only team averaging less yardage per pass than per rush? NC State. I don't think I need to point this out, but I'll do so anyway: that negative pass attempt/rush attempt differential is bad. Very not good.

Only Duke and Virginia are getting fewer yards per passing attempt than the Wolfpack. (Note also that these adjusted figures show Duke and UVA to be much closer in yards/pass.) On the flip side, the Pack has gotten good production out of its ground game--third behind Miami and those on-a-level-of-their-own Tigers.

It means NC State needs to run the ball more. Maybe a lot more. For one thing, State is getting more yardage per handoff than per pass. That's reason alone to run the ball more often. I think what we've seen isn't just extra passing because we're behind in games, but also Trestman's adjustment to other teams' adjustments. We're known as a running team, and that's what opponents key on. Trestman knows this, so he's trying to surprise them by passing more frequently. I've noticed that we aren't nearly as run-heavy on first down as we were last season. Trestman is doing what he can to keep the defenses honest. But based on the yards-per-carry numbers, why does he think he needs to? Ninety-seven runs in four games = a little over 24 per game. You'd expect the team with QB issues to need to throw more often; not the case with NC State.

Alas, because the team is poor this season, we're going to be in a lot of situations where we've got to comeback by throwing the ball. We may not be given the chance to play to our strength.