The Myth of Home Field Advantage

Complete Home Field Advantage Statistics

About a year ago, in my most widely read and discussed post to date, I detailed the hard facts of home field advantage. I showed that it was small, isolated stadiums that gave their teams the most boost on the scoreboard and not the rocking behemoths that we love so much. But some people just couldn't handle the truth. I now return to the topic to show how I was right and they were wrong (so suck it Trebek) . . . but also how I was wrong and they were right, as Yoda would say, from a certain point of view.

First, we need to cover some facts. Since 1994, when playing FBS opponents, home teams have won 60% of the time and have outscored their opponents by an average of about 10.5 points. In part, this is because lesser programs often take paychecks to travel and play bigger programs, home teams are more often better teams and therefore win more often.

Home field advantage, though, is very real. On average, home field advantage is about 3.5 points. Specifically, from 1994 to 2008 it was 3.500949. In other words, the home team could expect to do 3.5 points better on average playing at home than at a neutral site against the same team. There is a 7 point swing between playing at home versus playing at someone else's home-exactly 2/3 of the average margin of victory for home teams (10.5). The other 1/3 is because Louisiana-Monroe goes to Alabama and not vice-versa (oh, wait, bad example--suck it Saban).

To understand HFA, we first look at the point differentials (PD) or the difference in the average margin of victory at home versus on the road. Again, this is not my opinion, this is data. Over this period, Arkansas State has lost home games by an average of 1 point, but they have lost road games by an average of 20 for a differential of 19. The highest ranked BCS team is Texas A&M at 10, and there are only 7 in the top 25.

This, of course, does not actually measure HFA because it does not account for the strength of schedule. For example, Arkansas State's average home opponent was about 12.4 points worse than its average road opponent, so when we take that into account we see that Arkansas State had a 6.8 point HFA, or 13th best in the country.

After accounting for strength of schedule, Boise State and Hawaii come out on top. Oklahoma State is at 4, Texas A&M and Texas Tech at 8 and 9. Beaver Stadium comes in just a hair below Arkansas State at 14. You have to go to 39 with Florida before you find an SEC team.

These are facts-hard, undeniable facts--but there is more to football than point margins. Arkansas State has a real home field advantage, but getting less plastered at home is not anything to write home about.

So I decided to measure HFA as the oomph that helps a team win at home when they would lose on the road. This measure is a bit more technical, but the results are also a bit more satisfying. Interpreting the numbers is just about impossible, but the most important thing to remember is that teams with a larger number have been able to win more games at home that they would have lost on the road than are teams with smaller numbers.

Texas Tech is number 1, as Longhorn fans know all too well. Texas is 12, which might come in handy when they are looking for revenge against the Red Raiders this year. Florida State is at 3, showing the superiority of the tomahawk chop over the gator chomp, which comes in at 14. Despite the long home winning streak at Kyle Field in the 90's, Texas A&M drops to 26.

In summary, home field advantage means different things at different times. It helps almost all teams put more points on the board than their opponents (with the exception of Navy), and this characteristics of home field advantage seems to have less to do with big stadiums and raucous crowds than we might think. On the other hand, home field advantage helps some teams win when they might otherwise have lost. It might not show up in gaudy numbers, but Nebraska is able to win games in Lincoln that they would have lost somewhere else. And at the end of the day, that's what really matters. And Georgia plays better and is more likely to win on the road-go figure.

Home Field Advantage - Stage 2

New home field advantage post

Your aren’t going to like this.

I don’t like this and I wrote it. In my mind, it attacks the very foundation of the game I love so much. But I’m filled with a sense of academic integrity to report on my findings, even if I don’t like my findings. So bear with me and read with an open mind.

Home field advantage is very real. We can all agree on that. The professional athletes in professional sports, the older, hardened men and women of athletics, are influenced by the venue in which they play. In college football, with huge stadiums looming over young kids playing an emotional game, the effect is magnified. This, for the college football fan, is what college football is all about. This is why 75% of the ACC sucks.

But what creates home field advantage? The screaming fan likes to believe that his perturbation of air molecules, along with the butterfly in China, prevented an opponent’s audible on third and long or inspired the corner to make that extra effort and break up the pass. Or maybe his prayer was so heartfelt and sincere that God couldn’t resist interceding on his behalf.

Those with experience in the game also have felt the affect of riding long hours on a bus or plane and dressing in a pink locker room, just a little dehydrated, just a little tighter than usual, just a little distracted by an unfamiliar environment.

One goal of mine since establishing this blog was to quantify home field advantage. Early on, I found consistently that home field advantage across the country in college football was worth about 3 to 3.5 points. But how does that vary by team?

When I started, I was hoping to produce a list like this one offered up by a wizened reader:

1. LSU
2. Florida
3. Tennessee
4. Oregon
5. Ohio State
6. Penn State
7: Auburn
8. Washington
9. Clemson
10. Wisconsin

With a few minor changes to match my own biases (e.g. my personal opinion of ACC football). But I had to do this statistically, objectively, and reproducibly.

For my purposes here, home field advantage is defined as the opponent adjusted differential between home and road performance. A good home field environment can also work in other ways—it aids recruiting, it inspires future and current boosters to open their check books, it fills the athletes with a sense of pride and respect for their program that improves the work in practices, etc—but I’m not concerning myself with these for now. This analysis looks exclusively at the difference between how a team performs at home and how it performs on the road.

With that in mind, I think it is also important to establish that an “advantage” in college football that doesn’t show up on the scoreboard is not really an advantage. Sure, it might be fun to hold out your arms and slap them together like a giant reptile with 75,000 other people, but if it doesn’t show up on the scoreboard its just entertainment, it's not an advantage.

Using all games since 1987 as my sample, after controlling for the strength of the team and its competition and removing teams with an insufficient representation, I found that almost every team in the country has experienced a home field advantage (with the notable exception of Navy which apparently plays better in the more liberal environments outside of Annapolis).

The teams on the list above do not fare well. Tigers in cages, stadiums that seat small metropolises, and a thousand combined years of tradition aside, LSU comes in behind La-La and Louisiana Tech, Ohio State behind Ohio and Kent State, and Penn State eeks out an extra .2 points at home than Pitt in their oversized, undermanned condiment stadium.

Instead, coming in at number 1, and with little doubt, are the Rainbow Warriors. The distance a team must travel to play Hawaii (and Hawaii must, in turn, cover to play anyone else) seems to be the most important home field advantage in college football-because it definitely it's not the intimidating environment of Aloha Stadium.

After that, the list seems rather random. Blue fields are apparently difficult to adjust to. And instead of Oregon cracking the top 10, Oregon State takes a proud spot at number 3.

These results disturbed me, so I went in search of an explanation. I tried to looking at conference games (and all games in weeks 5-12 for independents) in an effort to control the sample bit, but the list looks similar-- still dominated by the WAC.

I next thought that I might find something in close games (final point margin was 7 or less), where the crowd has the most effect. Instead, I found that home field advantage almost disappears completely. This, I thought, was the most condemning evidence of them all.

(Click to see a larger version)

For completeness, I've also included 95% confidence intervals. This means that you can be 95% confident that the real value of the team's home field advantage lies somewhere in that range.

My first, second, third, … , and tenth reactions to all these results were that there must be something wrong with my analysis, something wrong with the data, something wrong with my computer, my statistical package, the interaction of electrons on the atomic level or the universe as a whole. NO WAY does No. Illinois get more of an advantage at home than every team in the country with a stadium that seats more than 80,000. I’ve been at those games, and yelled for my team and I know in the depth of my soul that I had an impact—but apparently I, we, were just a little delusional. The reason my team wins at home is because the opposing team had to eat something different for their pregame meal, left their lucky socks at home, spent too many hours commuting and then couldn’t find the restrooms once they arrived.

But go and yell your heads off anyways, pace in the living room, curse, swear, pray, and curse some more and refuse to change your underwear if you think it helps. That’s the Atlas of college football.

P.S. I have two more ideas that will take me a little longer to apply but may interest the engaged fan. I'm going to control for the field surface and the distance traveled to see what results that gives me, but it will take me a little while to organize all the data and design the analysis, but stay tuned.

Week 10 Recap and the Field Goal Calculator

With one game left this weekend, I thought it was about time to report on the initial results from the Matrix's first weekend. All in all, things have gone well. The Matrix correctly picked the winner in 38 of 53 games and was 27-21 against the line.

And it could have been better. If you look back at the picks (table) from last week, you might notice that Oregon is listed as the road team against Arizona State. Unless Arizona State has decided to start playing its home games thousands of miles from home, this is a typo. The Matrix gives teams a bonus if they are playing at home, and, in this case, gave Oregon's "at-home" credit to Arizona State. This mistake shifted the prediction, in this case, by about nine points. In other words, if the Matrix would have been fed accurate data, it would have been correct.

Then there is Rice and Texas. After ragging on these two teams last week, they put up a combined 52 points in the 4th quarter to win and cover the spread. Cincinnati put up 31 in the 1st quarter to do the same. And then the Demon Deacons felt the Cavalier curse and missed what would have been the winning field goal in the last seconds.

But I found a more worrying issue when I looked more closely at the results from the Matrix. Against the line, the Matrix was 0-2 when it gave one team an 80% chance or greater of covering. One, which I mentioned before, was Rice and their 20 point comeback. The other was Iowa State, who seems to actually be a much better team these days. The Matrix was most accurate when it gave one team only a small advantage.

The game of the week, in my opinion, lived up to its billing (that I gave it). Navy wins in triple overtime on a failed two point conversion attempt. Historic. I'm a bit biased towards the midshipmen - I love to watch their offense - but how could anyone that isn't a Catholic not jump on the Navy bandwagon after that game.

The Field Goal Calculator

The field goal calculator is my initial attempt to create an adjustable system that can estimate the number of points that a team will get on average if they kick a field goal or go for it on 4th down. The calculations come from an earlier blog and are not, by any means, perfect, but I think it is a good starting point.

Here, I have provided an excel spreadsheet so users can play with it themselves. The spreadsheet has 4 entries and a graph. You can adjust it for the leg strength of the kicker (average = 0), the accuracy of the kicker (average = 0), the average yards per play for that team, and the number of yards the team needs to get a first down. The graph shows how many points that team could expect to get if they went for it or if they kicked the field goal from various points on the field.

Download Field Goal Calculator.xls