Stat Boy Saturday: How Much Does Winter Weather Really Decrease Offense?

Another week with our honorary stat boy, Zach Fein of Fein Sports. A contributor with as much stat muscle as anyone in the business. You may not understand what he's says and use it for your fantasy leagues, but if you're in the mood to be baffled and confused, then boy does he have you covered. Because life is one big spreadsheet. This week he looks at whether the winter weather (alliteration!) really hurts offenses, or if it's just a myth. You remember this game. You know, the one where Tom Brady and Randy Moss killed their owners after lifting them through many an undefeated regular season? Or this one? The one where waiver wire hero Derek Anderson put up a stinker in a blizzard? I owned both of them last year. Anderson's terrible performance knocked me out of one league. As for Brady ... well, let's say I didn't even make the playoffs with him. And Frank Gore. And Wes Welker. And Ryan Grant. Uh, but I did get stuck with Lee Evans and Donald Driver. (I had the fourth-most points scored but finished in eighth place. Head-to-head will do that to you.) Back on topic. It's no surprise that Lambeau Field often has two or three snow games per year, as does Gilette Stadium in Foxborough. And because the Georgia Dome is, um, a dome, it should yield higher scores than usual. But the key word is "should." The question is, does the Georgia Dome really increase scoring, and does Lambeau Field and other cold-weather stadia lower scoring and other measurements of offense? I ripped off of MLB's Park Factors, which in its simplest form is equal to home runs per game (by both teams) divided by road runs per game (by both teams). So if the Louisville Sluggers score four runs per game and give up five at home, but score five and give up five on the road, their park factor would be equal to .9 (nine divided by ten). I used a more complex method, which is described in the "How I Calculate PF" section here. I did this for points scored, passing yards, and rushing yards, using week-by-week data for all December games since 2003. Conventional wisdom says that the cold weather should lower passing but increase rushing (due to the fact that both teams wouldn't be able to pass). Is that true? Here's the data.

NFL Stadium Factors

Team	Stadium	Point	Pass	Rush
Baltimore Ravens	M&T Bank Stadium	1.20	1.04	1.09
Houston Texans	Reliant Stadium	1.14	1.13	1.01
Minnesota Vikings	H.H.H. Metrodome	1.10	1.06	1.04
Atlanta Falcons	Georgia Dome	1.10	0.94	0.88
St. Louis Rams	Edward Jones Dome	1.06	1.14	1.32
Miami Dolphins	Dolphin Stadium	1.06	1.18	1.15
Tampa Bay Buccaneers	Raymond James Stadium	1.05	0.89	1.07
San Diego Chargers	Qualcomm Stadium	1.05	1.07	1.07
Philadelphia Eagles	Lincoln Financial Field	1.04	1.07	1.07
Seattle Seahawks	Candlestick Park	1.01	0.90	0.91
New York Jets/Giants	Giants Stadium/Meadowlands	1.01	0.94	0.99
Pittsburgh Steelers	Heinz Field	1.00	0.99	1.03
Indianapolis Colts	RCA Dome/Lucas Oil Stadium	1.00	1.09	1.01
Washington Redskins	FedExField	1.00	1.04	1.07
Oakland Raiders	Oakland-Alameda County Coliseum	1.00	1.16	1.00
Buffalo Bills	Ralph Wilson Stadium	0.99	0.86	1.02
Detroit Lions	Ford Field	0.99	0.99	0.91
Dallas Cowboys	Texas Stadium	0.99	0.98	0.84
San Francisco 49ers	Qwest Field	0.99	1.02	0.85
Arizona Cardinals	University of Phoenix Stadium	0.99	0.98	0.96
Chicago Bears	Soldier Field	0.98	1.00	1.16
Tennessee Titans	LP Field	0.97	1.05	1.20
Kansas City Chiefs	Arrowhead Stadium	0.97	0.94	0.89
Denver Broncos	Invesco Field (Mile High)	0.96	0.98	0.94
Cincinnati Bengals	Paul Brown Stadium	0.95	0.91	0.96
New Orleans Saints	Louisiana Superdome	0.94	1.06	1.08
Cleveland Browns	Cleveland Browns Stadium	0.93	0.90	0.89
Jacksonville Jaguars	Jacksonville Municipal Stadium	0.93	0.96	1.00
Green Bay Packers	Lambeau Field	0.90	0.88	1.04
New England Patriots	Gillette Stadium	0.90	1.02	1.04
Carolina Panthers	Bank of America Stadium	0.89	0.98	0.89

Methodology note: Two teams, the Cardinals and Colts, moved into new stadia during five-year sample used. I discarded this fact, because I was more trying to see if the weather, not the stadium, had an effect. The Browns, Packers, and Patriots are all near the bottom of the points factor, as they should be. But the Panthers last in the league? Surely this had to be a result of an abnormally-high road point scoring trend, right? I realized that with the low sample size (only 24 games worth for all teams, but 52 for the Giants/Jets), there must be a bias in the data. To fix this I switched the road points/passing yards/rushing yards per game with the leave averages over this time, which was 42 points, 409 passing yards, and 245 rushing yards. Here are the adjusted factors.

NFL Adjusted Stadium Factors

Team	Stadium	Point	Pass	Rush
Atlanta Falcons	Georgia Dome	1.07	0.99	1.05
Seattle Seahawks	Qwest Field	1.05	1.00	1.02
Minnesota Vikings	H.H.H. Metrodome	1.05	1.05	0.97
Tennessee Titans	LP Field	1.05	1.03	1.00
Kansas City Chiefs	Arrowhead Stadium	1.04	1.04	1.01
St. Louis Rams	Edward Jones Dome	1.04	1.03	1.03
Indianapolis Colts	RCA Dome/Lucas Oil Stadium	1.04	1.08	0.96
Baltimore Ravens	M&T Bank Stadium	1.03	0.99	0.97
Arizona Cardinals	University of Phoenix Stadium	1.03	1.03	0.91
Houston Texans	Reliant Stadium	1.02	0.98	1.01
San Diego Chargers	Qualcomm Stadium	1.02	1.00	1.01
Philadelphia Eagles	Lincoln Financial Field	1.02	1.02	0.98
Detroit Lions	Ford Field	1.02	1.04	0.95
Miami Dolphins	Dolphin Stadium	1.01	1.02	0.96
Cincinnati Bengals	Paul Brown Stadium	1.01	0.98	1.01
Denver Broncos	Invesco Field (Mile High)	1.00	1.00	1.04
Buffalo Bills	Ralph Wilson Stadium	1.00	0.88	1.04
San Francisco 49ers	Candlestick Park	0.99	1.02	0.95
New York Jets/Giants	Giants Stadium/Meadowlands	0.99	0.94	1.01
Dallas Cowboys	Texas Stadium	0.99	1.05	0.94
Oakland Raiders	Oakland-Alameda County Coliseum	0.98	1.01	0.96
Pittsburgh Steelers	Heinz Field	0.98	0.98	1.01
Tampa Bay Buccaneers	Raymond James Stadium	0.97	0.92	1.02
Washington Redskins	FedExField	0.97	0.97	0.99
Jacksonville Jaguars	Jacksonville Municipal Stadium	0.96	0.96	1.02
New Orleans Saints	Louisiana Superdome	0.96	1.02	0.94
Chicago Bears	Soldier Field	0.96	0.98	0.98
Green Bay Packers	Lambeau Field	0.96	0.94	1.00
New England Patriots	Gillette Stadium	0.94	0.99	0.93
Carolina Panthers	Bank of America Stadium	0.92	0.98	0.93
Cleveland Browns	Cleveland Browns Stadium	0.90	0.92	1.06

What do you know, the Panthers are still at the bottom of the list. I would call that an aberration¹. Four of the bottom five teams are all in snowy, cold-weather portions of the U.S. Four of the top seven teams are all in domes. See a trend? Yes, the wintry weather does affect offenses, especially in the selected cold-weather stadia. If you have Braylon Edwards, don't be afraid to bench him for someone such as Anthony Gonzalez during the fantasy playoffs. When Aaron Rodgers and Matt Forte put up sub-par games when the Packers and Bears face each other in Week 16, don't say I didn't warn you. ____ ¹I update a list of these stadium factors weekly on my Web site, using data from 2005 through the current week. The latest edition has the Panthers exactly average in the points factor. We would never shoot ourselves in the leg. FFWritersWithHair@gmail.com