# Does Peyton Manning Play Worse in Cold Weather?

If you’re a believer that Peyton Manning plays worse in cold weather, the last few weeks have only strengthened your resolve. In 3 of his last 4 games, he’s played in temperatures below 40 degrees, and come out with a record of 1-2. In his other “warm weather” games this season, Manning has a record of 10-1. This continues a theme that has plagued Manning his entire career, that he underperforms when the temperature goes south.

But will the statistics support that theory?

# Peyton’s Statistics in Cold Weather Games

Thanks to an article by the Mile High Report, I was able to obtain data on every one of Peyton’s games where the temperature was at or below 40 degrees. They had 21 such games, all from 2012 and earlier. I added three more games from 2013 and threw out the 2010 game against Buffalo (Peyton was pulled after the 1st quarter because the Colts already had already clinched home-field advantage throughout the playoffs). So I ended up with 23 games where Peyton played in “cold weather”. You can get the data I used here.

Manning’s record in those 23 games is 11-12. Not very good for a player whose career winning percentage is 0.693. But we’re going to dive deeper than simply wins and losses and look at his individual statistics. The following table compares his cold weather numbers with his career averages. And to let you know, the average temperature in his cold games was 31.9 degrees.

 Career Cold Weather Difference Completion % 65.4 63.1 2.3 Yards/Attempt 7.7 7.5 0.2 QB Rating 96.9 86.2 10.7

We see that the differences for completion percentage and yards per attempt are negligible. We do see that his QB Rating is over 10 points worse in the cold weather games, but keep in mind our sample size is only 23. We should perform a 1-sample t test to determine if this difference is actually statistically significant.

It’s really close. The p-value isn’t less than 0.05, but it is less than 0.1. So if we used an alpha value of 0.1, we would be able to conclude that Peyton Manning has a worse QB rating when he plays in cold weather.

But hold on, is cold weather the only factor?

We should be wary of a lurking variable. That is, a variable that is not included in the analysis but may affect the interpretation of the results. And that lurking variable appears to be the fact that Peyton has played 19 of the 23 cold weather games on the road. For his career, Peyton’s QB Rating at home is 100.1, while on the road it is 93.7. So clearly part of his poor play in cold weather games is due to the fact that so many of them have come on the road.

Manning’s cold weather numbers are often compared to Tom Brady’s. But that’s not really fair, since Brady gets to play most of his cold weather games at home. If only there were another great quarterback in the NFL that played most of his games in a dome who we could look at and see how he performed in cold weather. Oh wait………Drew Brees!

# The Drew Brees comparison

I used pro-football reference.com to collect data on cold weather games for Drew Brees. I only used years where he played for the Saints (2006 and on) to get the dome to cold weather comparison. He has played in 10 such games, although I did include 3 games where the temperature was 41 and 42 degrees to increase the sample size (I say it’s close enough to the 40 degrees I used for Manning). The average temperature of those 10 games was 34 degrees, similar to Manning’s average temperature. Here is how Drew's cold weather numbers stack up against his career numbers.

 Career (in New Orleans) Cold Weather Difference Completion % 67.2 64.3 2.9 Yards/Attempt 7.7 7.1 0.6 QB Rating 98.9 88.1 10.9

The difference between Drew Brees’s career numbers and cold weather numbers are all greater than Peyton! Of course, 10 games is a very small sample size (though 23 games isn’t that large either). So let’s do our due diligence and see if the difference in QB rating is statistically significant.

Holy cow, the p-value is 0.03!  Even with the small sample size, we can conclude that Drew Brees' QB rating in cold weather games is significantly lower than his career average in New Orleans! The reason is that Brees has a lot less variation. Manning’s QB rating in cold games ranges from 31.2 to 157.5, which results in a standard deviation of 33. Meanwhile, Brees only ranges from 67.2 to 120.3, which results in a much smaller standard deviation of 16. So even with a similar difference and a smaller sample size than Manning, we’re able to get a smaller p-value.

And to make matters worse for Brees, his record in those 10 games is 3-7. That’s terrible when you compare it to his New Orleans winning percentage of 0.632. With all this information, we can definitely conclude that Drew Brees plays worse in cold weather, right?

Well, just like we did with Manning, you have to consider other factors that might be in play, like where the game was played. All 10 of the games I used for Brees occurred on the road. And just like Manning, Drew Brees has a lower QB rating on the road than he does at home (99.9 compared to 90.4).

The fact is that if you take any great offense that plays in a dome and make them play on the road outside of a dome, they’re not going to be as good, regardless of the temperature. What’s happening with Manning and Brees is that we’re taking their career numbers (a majority of which occurred inside a dome), and comparing it to a small subset of games that occurred on the road outside of a dome. Of course their statistics are going to be lower! Might some of the reason be the cold temperature? Sure. But I believe a majority of the reason is simply the fact that they’re playing on the road.

But this still leaves one more question. If Manning and Brees both appear to play worse in “cold weather games”, why do people constantly talk about Manning and cold weather games but never mention Brees?

# Why do we focus on Manning?

Here is how Peyton Manning exited the playoffs in the 2002, 2003, and 2004 NFL seasons.

• 2002: Lost to the Jets 41-0. Temperature was 34 degrees. QB rating of 31.2.
• 2003: Lost to the Patriots 24-14. Temperature was 31 degrees. QB rating of 35.5.
• 2004: Lost to the Patriots 20-3. Temperature was 27 degrees. QB rating of 69.3.

That’s 3 cold weather losses in playoff games where everybody was paying attention. In the age of 24/7 sports coverage where we try and explain everything, this is all it took to get the narrative going.

Never mind that in the playoffs you face better teams. Never mind that all three games were on the road. Never mind that the week before the 2003 loss to the Patriots, Manning had a 3-touchdown, 300-yard playoff win at Kansas City in cold weather. These three games were proof that Manning plays worse in cold weather!

Meanwhile, Drew Brees has had one playoff game in cold weather, a 39-14 loss to Chicago in the NFC Championship game. It was 27 degrees that day, but since it was the only time he’s failed in cold weather in the playoffs, the media pretty much ignored it. And they’re definitely not going to remember the slew of regular season games Brees lost in cold weather. The playoffs are where it’s at!

But if there was ever a chance for Peyton to dispel his cold weather characteristic, this is the year. Denver should be able to clinch hold field advantage throughout the playoffs, meaning Manning will get some home playoff games in cold weather as opposed to going on the road (I know he had one last year, and it’s really too bad Peyton made a terrible play on the ball and allowed Baltimore to score on a 70-yard touchdown pass with 31 seconds left). And then the Super Bowl will be played in New Jersey…in February! There’s potential for 3 cold-weather games, none of them having to come on the road. Of course, if he loses just one of them, the narrative will continue. But if Peyton wins them all, the media won’t know what to do. Their cold weather narrative will be dead!

Then again, there is always Drew Brees…

Name: Pat Peterson • Friday, January 3, 2014

I would be curious to see what the data looks like for quarterbacks that played a fair number of home games in cold weather (Favre, Rodgers and Brady come to mind). Do they have better "cold weather" stats at home vs. the road?

Name: Kevin • Thursday, January 16, 2014

Pat,

I ran looked at the numbers for Rodgers. In the 17 games I found where he played at home in temperatures lower than 40 degrees, he has a QB Rating of 107.8. This is pretty much the same as his overall QB Rating at home of 109.1. So at home, the cold weather doesn't seem to affect Rodgers at all.

I only found 6 cold weather games that Rodgers has played on the road. His QB Rating in those games is 90.2. His QB Rating for all his away games is 101.

So now imagine that Rodgers played in a dome. We would point to those 6 "cold weather" games and say how much worse he performs in cold weather. But you notice that at home, the cold temperature doesn't affect him at all (and it's the bigger sample). So I think Rodgers helps show that the difference in Manning's "cold weather" games has more to do with them being on the road than the actual temperature.

Kevin