Fantasy Impact of December Weather

The cold northern weather has brought some of the most exciting games in the history of the NFL including the famous “Ice Bowl” and the “Tuck Rule Game”.  It is very tough for some teams to have to play in stadiums such as Lambeau Field or Soldier Field in December because the weather forces them to adjust their game plans. December is also time for the fantasy football playoffs and fantasy football players also often have to adjust. You may start a running back playing in the cold because he is likely to have more touches or a quarterback playing in a dome because the weather will not affect his performance. Every year fantasy football players have tough decisions to make later in the year but this made me think: should cold weather affect your draft strategy?

For this analysis I used statistics from 1999 through 2008. My initial idea was to compare fantasy points earned by the pass and by the run in different stadiums in December with fantasy points earned from September through November in those same stadiums. However there are many factors that can affect fantasy points scored other than weather and we don’t have enough data to minimize the error. For that reason I used passing yards and rushing yards which are not perfect but should offer much more consistent results considering our data sample. We will also work under the assumption that if there are less passing yards, the chances of a passing TD being score are lower.

The first step was to calculate the average number of rushing yards and passing yards in each stadium from weeks 14 to 16 from 1999 to 2008. After that, I divided that number by the number of rushing yards and passing yards that the teams playing in each stadium averaged throughout the season. For example, in 2008, the only game played in Gillette Stadium between weeks 14 and 16 was in week 16 between the Patriots and Cardinals. In that game the Patriots passed for 331 yards, ran for 183 while the Cardinals passed for 142 and ran for 44 yards. That is a total of 473 passing yards and 227 rushing yards in that game between both teams. Throughout the season, the Patriots averaged 223 passing yards and 142 rushing while the Cardinals averaged 292 passing and 74 rushing. Add those numbers together and those two teams combined for 515 passing yards and 216 rushing yards per game for the entire season. I then divided 473 by 515 and 142 by 216 which gives 0.92 and 1.05. Those numbers are the scores for Gillette Stadium for the 2008 season. I did the same calculations for every stadium from 1999 through 2008 and averaged them.

The next step was to group the stadiums based on their average December weather. Here are the groups I used:

Now here are the results of my analysis for each group:

As you can see, it is not a myth that there is more running and less passing in low temperatures. Teams playing in very cold stadiums in December have about 12% less passing yards and 12% more rushing yards per game than they do for the entire year. These numbers will vary from year to year and when there was a big snowstorm in 2007, those numbers went up to 25% in very cold stadiums and 15% in cold stadiums. These are very interesting statistics but the question still remains whether or not this should affect you drafting strategy.