Comments on Advanced NFL Stats: The Best Defensive Player in the NFL is...Neil Rac...

THIS IS AWESOME!!!! Just came upon your website &...

2012-01-31T23:10:54.975-05:00

THIS IS AWESOME!!!!

Just came upon your website & there is sooo much to read & absorb I can;t wait to digest it all

Thank you!

Yeah, there's certainly a ton of noise and varianc...

2007-12-19T18:49:00.000-05:00

Yeah, there's certainly a ton of noise and variance to it. In addition to returners, I think you have to consider blocking. I remember Deion complaining during his year in Washington that the blocking wasn't as good as it was in Dallas. Personally I think Deion was mostly getting old fast, but there was probably some truth to the blocking being worse.

It would be a tough task to tackle in a comprehensive study. You have to separate (and possibly discard) the effects of kicker, coverage teams, returners, blocking, and weather/altitude. And then there's edge effects - does the return team get some sort of credit on squibs or out of bounds kicks?

FO's analysis of field position is buried in their...

2007-12-19T15:44:00.000-05:00

FO's analysis of field position is buried in their turnover paper, but you're right they do seem to understand it. But their kick off article was all very qualitative. Maybe it's because it was intended for a more general audience.

(I think they got their field position value chart straight out of Hidden Game of Football. I actually came across that very article just the other day. I haven't read the book myself, but it's on my list.)

Just watching special teams, it seems very chaotic and random. Plus, there aren't as many iterations of punts or kicks as there are offensive and defensive snaps. So we'd expect less of a random component in the outcome of off and def than ST.

I just read an column yesterday from the Dallas Morning News by Rick Gosselin about how there are so many more kick return TDs this year, somewhat because teams don't use starters on coverage teams like they used to.

I agree that kickoff depth wouldn't explain all of the consistency, but I'd bet a good chunk of it. Some of it might have to do with the kick returners a team faces. The NFC North has to kick to Devin Hester a lot more often than most other teams.

Elam hasn't done kickoff duty since 2002. But y...

2007-12-19T12:39:00.000-05:00
Elam hasn't done kickoff duty since 2002. But you're right about the effect of air density.

Right, of course. And there's Ernster at the top of the list. So it's safe to say that altitude matters.

You're right that this doesn't change the main conclusion (long kickoffs are very important), although it does call into question whether the rankings you gave are reliable.

FO was evidently on to something. But it's not clear they understood why or could quantify the importance of kicks and punts.

I think it's pretty clear how FO would quantify that importance. They assign an expected point value to field position, much like the Romer study. I'm not sure their table is exactly the same, but I'm sure it's very similar. That's how they come up with their special teams rankings.

You've certainly added to their explanation by, essentially, separating the kicker from the coverage teams.

One thing that remains to be examined is the return and coverage team importance. I'd expect that they are predominantly random, and kick depth is the one component that is consistent.

While the year-to-year correlation of coverage teams is not nearly as consistent as offense and defense, it does have some consistency. I would be surprised if this could be entirely explained by kickoff depth. Some teams devote more roster spots to gunners and/or use more of their best athletes on coverage teams, and it's reasonable to expect this would have some impact.

Elam hasn't done kickoff duty since 2002. But you'...

2007-12-18T20:15:00.000-05:00
Elam hasn't done kickoff duty since 2002. But you're right about the effect of air density. It would slightly affect the rankings of the kickers, but not change the overall significance of the field position.

FO was evidently on to something. But it's not clear they understood why or could quantify the importance of kicks and punts. This result appears to confirm and explain their theory.

One thing that remains to be examined is the return and coverage team importance. I'd expect that they are predominantly random, and kick depth is the one component that is consistent.

I agree and would sign the big leg. I'd also go for it on 4th down a lot more often and not worry about FGs so much. (More on that later.)

I don't see Elam on the list. Did you omit him in...

2007-12-18T17:46:00.000-05:00
I don't see Elam on the list. Did you omit him intentionally to avoid the mile high effect? This brings up the broader point that kickoff distance is almost certainly affected by weather. This is much more intuitively clear than it is for field goal accuracy. The kicker is basically kicking as hard as they can with little concern for accuracy, so physics of air resistance dictate how things work out.

Good point on how most media sources ignore this aspect of kicker performance. One of Football Outsiders' basics is "the most underrated aspect of an NFL team's performance is the field position gained or lost on kickoffs and punts". I would certainly be more interested in average kickoff length than field goal percentage if I were signing a kicker.

It would be nice if you could throw a "hang time" variable into that regression, but unfortunately that data isn't readily available.