NFL Referees 2007 Week Two Report

Not too much to report just yet for a few reasons -- the statistical sample size is still small after only two weeks and it is hard to tell tendencies of the teams themselves (how good are they and how many penalties would they ordinarily commit in an average week?).

So for now, just a few brief observations:

After two weeks (just as after one week), there is a positive correlation suggesting that home teams do better with referees that on average call more penalties. The correlation after two weeks is +0.267 when comparing the number of penalties per game and the rate that home teams win that referee's games.

There still is not much correlation between the full 2006 season and the first two weeks of the 2007 season as you go referee by referee. There is a negative correlation for the penalties per game and home team's winning percentage for the referees that worked in 2006 and 2007 so far.

Walt Anderson and Ron Winters refereed games in week two after taking week one off according to the NFL official reports. The only one from 2006 that has not appeared this year so far is Bill Vinovich. After week two, the referees with the most penalties per game are Bill Leavy, Terry McAulay, and Walt Anderson. The ones with the least penalties per game are Gerald Austin and Jeff Triplette (tied) followed by a tie between Bill Carollo and Larry Nemmers.

NFL Referees 2007 Week One Report

The start of the 2007 NFL season! Including all games from week one (ending Monday, September 10, 2007), there are only a few trends or comments that we can make. As the season goes on, we will compile more data and be able to make more analysis, especially trying to see trends that carried over from the 2006 season to the 2007 season.

Do refs who call lots of penalties increase the odds the home team will win?
There seems to be a positive correlation between referees that call a large number of penalties and the odds that the home team will win the game. There was a positive correlation in the first half of 2006, the second half of 2006, and the first week of 2007. We'll keep an eye on this as a possible correlation. So perhaps the answer to this question is yes.

Does the rate that refs call penalties carry over to the next season?
In general, it seemed to have a carry-over from 2005 to 2006 so we expect to see this in 2007 also. But strangely enough, it didn't show up in week one, perhaps due to limited data. The strange variation was severe. Walt Coleman called the least number of penalties per game in 2006 (9.3) but had the most in week one (16). Very strange. Bill Leavy had the third-least in 2006 (9.9 per game) but tied for second-most in week one (15). We think the answer is yes, but it wasn't true in week one.

Who are the new refs and who is no longer referreeing?
According to the official NFL statistics, the new referees in week one were Barry Anderson and John Parry. Welcome, guys! Referees from 2006 that did not referee in week one were Walt Anderson, Bill Vinovich, and Ron Winter. Are they going to show up later this season? We'll see.

NFL Season 2007!

Finally, the 2007 NFL season has begun! Unlike most sports writers, I won't be offering any pre-season predictions for the year. It is hard to predict trends from year to year, but that is something that I will be taking a quick look at as the season progresses -- seeing how much of a correlation there might be between the 2006 and 2007 seasons for the referees.

Post a comment with your suggestions or ideas of what may be useful to track in the coming year. I have been basing my analysis on the official box scores that are available on the NFL web site a few hours after the games end.