Home-field advantage is, by definition, an advantage. Most NFL fans think that because a game is at a team’s stadium, that the home team will have an upper hand. Whether it is crowd intimidation or whatever x-factor that stadium might produce, this notion of home-field advantage is widely accepted.
But is the ‘advantage’ in home-field advantage supported by statistics?
Basics Statistics of Home-Field Advantage
The short answer is yes. Over a large sample size, it is documented that the average NFL game is won by the home team by a score just below three points. What is even more telling is that, in the NFL, home teams usually win in between 55 and 60 percent of the time. So, speaking incredibly generally, if you want a winner, the home team isn’t a bad bet.
But how can we get more specific? How can we be more confident about that bet?
Let’s consider the home-field point differential mentioned earlier. Under three points isn’t very much. So, should we still trust home-field?
Here is a diagram of win percentage versus home field advantage in the NFL from 2012:
This tells us that regardless of a certain year’s point differential, the home team’s win percentage still hovers right below 60 percent and, in the past two decades, always stays above 50 percent.
Obviously, matchups matter. Home-field didn’t matter much for the Cleveland Browns from 2016 to 2018. But for more perennial playoff contenders, home field advantage is incredibly important.
Home-Field as a Team-by-Team Focus
Over the past decade, the teams with the top five home-field win percentages are the New England Patriots (84.7%), the Baltimore Ravens (75.0%), the Green Bay Packers (74.7%), the Pittsburgh Steelers (71.1%), and the New Orleans Saints (69.8%), respectively.
Each of these teams are what we would call perennial playoff contenders. Although some might have off-years, each of these teams has won a Super Bowl in the past ten years, as well as several playoff games. What does this mean to us? The Saints won the Lombardi Trophy all of eight years ago, right? Yes, exactly. The Saints are the perfect example of why home-field matters.
Since 2008, the Saints have only won their division three times, but they still have the fifth highest win percentage at home during that time. They have gone 7-9 in four seasons since 2008, but still maintain their solid win percentage at home. This is because home-field matters. Using a large enough sample size, we can see that some teams simply perform better at home. You can choose to believe whether it’s the crowd or not, but the statistics don’t lie. Before betting on a winner, check their historical home-field win percentage.
Debunking the Myths of Home-Field Advantage
Now, let’s get rid of a common myth.
Arrowhead Stadium in Kansas City is notorious for being a tough place to play. It’s the loudest football stadium in the world, but that doesn’t mean the Chiefs are always a good bet at home. Excluding this season, since the 2013, the Chiefs have gone 53-27. They’ve lost an incredible 13 of those 27 games at home. So, 48 percent of the Chiefs’ losses over the past five years have come in the loudest stadium in the world.
So, we have one team that historically wins at home in the Saints, and the opposite in a Kansas City team that performs surprisingly poor at home despite five straight winning seasons. This information allows us to understand that home-field advantage is malleable. It bends based on the weight of each team. I used the statistics about the Saints and Chiefs to show that the appearance of an inherent stadium advantage is completely different from what is what we desire: a home-field advantage based simply off winning.
The Chiefs still have a home-field win percentage of over 50 percent. But the myth that notoriously loud, ‘x-factor’ of a stadium dictates home-field advantage is a fallacy.
But this myth has two sides.
At the beginning of the 2017 NFL season, 247sports.com ranked all NFL stadiums from easiest to toughest to play in. They ranked the Atlanta Falcons’ new Mercedes-Benz Stadium as the 23rd hardest place to play in the NFL. We have to cut them some slack because the stadium was new, but 23 was way too far down for the Falcons. They have the eighth best home win percentage in the NFL since 2008 with 65.9 percent. On the flip side, just because a place isn’t as rowdy, doesn’t mean it’s not tough to play in.
So, that’s home-field advantage. It depends on the team, but overall, the statistical consensus is that a team playing at home is more likely to win by a few points. Considering the matchup and historical home-field performance is important as well.
But what about playoffs? That’s the time of the year that most fans say home-field advantage matters the most. Well, most fans are correct.
Home-Field Advantage in the Playoffs
Check out this diagram:
This shows us that for most of the twenty-first century teams with home-field advantage in the playoffs have a better win percentage than those during the regular season. There is significant importance of home-field advantage in the playoffs.
But, does that importance stretch to all playoff games?
This graph lets us understand that the Wild Card round is different than others in terms of home-field. From this we can infer that, historically, the higher the seed you are, the more likely you are to win later in the playoffs. A 65.4 percent win percentage is substantially higher than than the regular season percentage of around 57. This is proof of how important it is for playoff contending teams to win late in the regular season. Just ask Tom Brady. Out of the seven AFC Championships that the Patriots have hosted, he’s only lost one at home.
The lesson here: during the regular season, consider home-field a slight advantage, but, as the playoffs progress, think of it more as an asset.