Thursday, May 21, 2009

Sack And TFL Rates

Gobbler Country takes a look at sack and tackle for loss rates in conference play.

NC State defense:

1 sack per 21 opponent pass attempts (10th in ACC; league average: 1 sack/14.4 pass att)
1 TFL per 6.9 opponent rush attempts (4th in ACC; league average: 1 TFL/8.1 rush att)

NC State offense:

1 sack allowed per 11.3 pass attempts (9th in ACC; league average: 1/14.4)
1 TFL allowed per 12.6 rush attempts (2nd in ACC; league average: 1/8.1)

Correctly categorizing plays on which a sack occurred as pass plays rather than run plays, which GC does, removes some of the noise. But there's still the matter, especially in the Wolfpack's case, of QB rush attempts. Russell Wilson had 90+ carries in league play, and once you remove sacks from that figure, you've still got a bunch of carries that were a mix of pass plays and designed runs (20% designed runs, maybe?). Unfortunately, even with play-by-play data on hand, there's no way to tell which is which, though I think we can say generally that most of the time, Wilson's carries were making something out of a failed pass play.

(I'm not criticizing GC here, just lamenting the problem created by the lack of a simple notation next to each quarterback carry in the play-by-play.)

Considering that a dual threat QB uses his feet more frequently than a more traditional pocket passer does, it seems like the dual threat QB would create more inflation/deflation in the sack and TFL rates. In State's case, for example, the team had 265 carries (excluding sacks) in ACC play--more than a quarter of which were Wilson's. That's a fairly large amount of uncertainty.