Bill Simmons’ NFL Betting Theory: Does Cold Weather Impact Playoff Over/Unders?

Bill Simmons’ NFL Betting Theory: Does Cold Weather Impact Playoff Over/Unders? article feature image

David Butler II-USA TODAY Sports. Pictured: New England Patriots quarterback Tom Brady

  • Bill Simmons has an NFL betting theory: Cold weather impacts scoring and playoff over/unders.
  • Using our Bet Labs software, we tested Simmons’ theory to determine if his hunch is correct.

Stop me if you’ve heard this one before … Bill Simmons has an NFL betting theory. On the latest episode of The Bill Simmons Podcast, “The Sports Guy” and the guru of gambling, Cousin Sal, discussed the cold weather expected for Sunday’s AFC Championship game (6:40 p.m. ET, CBS).

Cousin Sal: “The weather means nothing, the points will come. I spent an hour and half looking for articles on this, how cold weather affects points. It really doesn’t, in some cases there are more points scored in the cold.”

Simmons: “So, this is an old wives’ tale, the weather does not affect the points. This sounds like a good challenge for our guy at The Action Network, John Ewing. If it’s under 20 degrees, I want to know how that affects the point total of playoff games.”

Challenge accepted.

Using our Bet Labs database, here is how NFL overs have performed based on the average temperature in all games since 2003:

In all games played in temperatures below 30 degrees, the over is 114-80-2 (58.8%). A $100 bettor wagering on the over in these frigid temps would have returned a profit of $2,780, since 2003.

Cousin Sal was right, cold temperatures do not impact scoring. The likely explanation is that there is an overreaction by casual bettors when the forecast calls for blustery conditions.

Oddsmakers know the public expects low-scoring games when there is cold weather and will adjust the total down anticipating action on the under. With a deflated line and less scoring needed, it is easier for overs to hit.

In general, it has been profitable to bet the over when temperatures approach zero degrees, but this doesn’t answer Bill’s question. The Ringer’s head honcho specifically wanted to know how the over/under performs in playoff games when the temperature is below 20 degrees.

As Simmons said on the podcast about Patriots-Chiefs on Sunday, “If it goes under 20, there is no way it’s a shootout.”

Since 1985, there have been 21 postseason games played outdoors in temperatures below 20 degrees. The over has gone 14-5-1 (73.7%) in these games, covering by 9.4 points per game. (Bears-Redskins in 1987-88 Divisional Round did not have an over/under listed.)

This is a small sample but it fits the overall trend of overs being profitable in cold weather games.

On Sunday, the early forecast calls for average temperatures of 13 degrees when the Chiefs host the Patriots in Kansas City. The over/under opened 59.5 and has been bet down to 57.

The line movement suggests bettors are expecting a low-scoring game, but history says overs have been profitable in freezing temperatures.