Wednesday January 11th, 2012

In the sport of table tennis, the emphasis on neutral playing conditions is a heavy one. So much so that even at low-level tournaments, the organizers will regulate temperature, humidity and the current from the arenas' air conditioning vents. Contrast with the NFL. Teams can play alongside the beach -- under a cloudless sky in 90-degree heat -- on one Sunday; and then play alongside one of the Great Lakes -- in a heartlessly cold blizzard -- the next Sunday.

There are, of course, two conferences and eight divisions in the NFL. But, especially at this time of year, we go so far as to classify teams by climate, distinguishing "cold-weather teams" from the "warm-weather teams," as if this were a critical factor for determining which team will win. The lines of demarcation vary, but the cold-weather teams generally include Buffalo, Pittsburgh, New York Giants, New York Jets, Philadelphia, Washington, Baltimore, Green Bay, Chicago, Denver, New England, Cleveland, Cincinnati, and Kansas City. The "warm" group is comprised of the others, many of whom play inside a climate-controlled dome, or under a roof when the weather turns disagreeable.

We hear it all the time: when a team from one climate travels to another, the home team has a sizable advantage. In some cases, the teams from the thermally-challenged regions will be unaccustomed to the heat and humidity, Eskimos in the Sahara. More commonly, the teams from the balmy climes will be addled by conditions that induce frostbite. This is climatic culture shock, the meteorological equivalent of a vegetarian in Texas or Mike Tyson in Salt Lake City.

Television accelerates this theme, invariably locking the cameras on those poor San Diego Chargers huddled around the heater behind the bench in Foxboro or the steam coming off the head of that hapless Tampa Bay Buccaneer marooned in Buffalo. Over the past month, pundit after pundit explained that once the Green Bay Packers clinched the best record in the NFC, the team would waltz to the Super Bowl. Why? Because Green Bay would be rewarded with home field and its conference rivals from balmy New Orleans and Atlanta and San Francisco would be severely disadvantaged playing on "the frozen tundra of Lambeau Field."

Except that it's a myth.

After studying data from every NFL game from every season since 1985 -- more than 6,000 games -- and matching the results to the outside temperature, wind, rain and snow conditions, we've found that cold-weather teams are no more likely to win at home when the weather is brutally cold. Nor are warm-weather teams more likely to win at home when the temperature is ruthlessly hot. And, the home winning percentages for dome teams immune from extreme weather conditions -- our placebo test -- do not vary with the weather any more than they do for cold- and tropical-weather teams.

Take even the most extreme cases: a warm-weather team such as the Dolphins has to play in the extremely cold weather of Buffalo; or a cold-weather team such as the Steelers plays in scorching Arizona heat. In both cases, averaging across all cold and warm weather teams over the last 25 years, there is little to no unusual effect on performance. Contrary to conventional wisdom, weather imbues a team no additional home advantage.

If we think about it, this makes sense, doesn't it? First, it tends only to be brutally cold or hot for a few weeks of the season -- mostly September for the heat and December for the cold. So it's not as though the Browns or Bills are going to draft or sign players based on their ability to adapt to those one or two home games a year played in miserable cold. (This isn't like a baseball team that plays all of its 81 home games in a park with a shallow left field porch and might therefore place extra emphasis on signing right-handed power hitters). Nor are these teams likely to feature an offense that takes advantage of the weather.

Second, just because players end up on warm- or cold-weather teams doesn't mean their bodies have adapted. Tim Tebow -- raised and schooled in Florida -- didn't become a cold-weather quarterback in Denver any more than, say, Dan Marino -- raised and schooled in Pennsylvania -- became a warm-weather specialist in Miami.

Green Bay may well win the NFC title. (And the Packers may well defend as champions of the Super Bowl -- which, incidentally, will be played indoors for the second straight season.) This will be for any number of reasons. Because Aaron Rodgers is an unsurpassed quarterback. Because Mike McCarthy is a savvy coach, somehow still underrated. Because the Packers' defense is a lot better than its ranking in the misleading "total defense" category would suggest. But it won't be because the players are better armored against the elements than their shivering opponents from the tropics. Fact is, it's cold as hell at Lambeau for all players on both teams, including Aaron Rodgers, who by the way, grew up and played his college football in sunny California.


Tobias J. Moskowitz, University of Chicago financial economist, and L. Jon Wertheim a senior writer at Sports Illustrated, are the authors of Scorecasting: The Hidden Influences Behind How Sports Are Played and Games Are Won. To order Scorecasting click here.

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