Wednesday, December 3, 2008

Field Position

Interesting piece in JS this morning regarding field position:

It doesn't look like much, but the fact that the Packers' average starting point this year is at their 27 compared with their 32 last season is statistically significant.

"If you get it out to the 32 on your initial possession, your scoring probability really increases," offensive coordinator Joe Philbin said.

[Curmudgeonly moment: I really hate it when people, and especially journalists, use science/math terms ("statistically significant") in a colloquial way. ]

I'm also somewhat skeptical that an additional five yards on any particular drive gives an offense much of an advantage as the Philbin quote suggests. No numbers to back up my feeling, but it doesn't seem right.

I suspect that what is really going on is that the average reflects fewer short field opportunities. (Starting from the 32 is not really a short field.) To use an example, its commonly stated that the "average life expectancy" in ancient times was, say, 18 years. I've met people who mistake that to mean that 18 year olds were dying all over the place. That's not the case. The reason the average life expectancy was so low was because infant and childhood mortality was so high. If you survived past childhood, you would likely live significantly past the age of 18.

Same thing here. The problem is not that the Packers are actually starting at the 27 versus the 32. I highly doubt that five yards on any given drive makes much of a difference. I suspect that the bigger problem is that that the five yard decline in average starting field position instead reflects that there are fewer starts from the 40, 45, 50, etc. I also suspect that even one extra short field opportunity per game could make all the difference in some of the close games the Packers have lost this season.


  1. "I really hate it when..."

    Have you ever noted how much you use this phrase?

  2. Honestly? No. But I guess I should starting paying attention.

    Thanks a lot.

  3. Just givin you a little grief. (You do us it quite a little bit.. ;)