After COVID-19 disrupted football, no more than it disrupted all of society and civilization across the world, and enforced a pause of several months, the games have recently restarted with the German Bundesliga the first of the major leagues to resume play. Games are played without fans, leading to a stark leveling of the home cooking used by teams to gain an advantage on their own territory. Playing at home confers a distinct advantage – everyone knows that. But the restart of football got me thinking about how much of an advantage is there really.
I draw upon a few data sets. I have match results for the Turkish Super Lig back the 1959/60 season, the German Bundesliga from the 1963/64 season, the full set of Premier League fixtures starting in 1992/93, and Spanish La Liga and Champions League results dating back to 2010/11. I have omitted details on the La Liga and UCL because the data set is small – and some fields have odd values that make me doubt the data integrity – but I have included them in the full file linked at the end. I also have events data (goals, bookings, penalties, etc.) for those seasons. Some of the earlier seasons of the Turkish and German leagues have missing data for certain event types so some seasons are omitted in the analyses.
First, I looked at the points advantage that home teams gain. After all, the long-term goal of every club is to accumulate points over the course of a season. I use a simple metric: net points gained per home game, calculated with simple arithmetic by subtracting the average points per game for away teams from the average points per game for home teams. At a very high level, across all of the data sets I looked at, recent trends show that home field confers an advantage of between 0.4 and 0.6 points per game. What is evident – more so in the German and Turkish data sets because of the larger data set – is that the home advantage has decreased over time. But it still exists and is significant.
Let’s look at each league’s trends. Note: I am using three points for a win to do the analysis regardless of the scoring rules in a given season in a given league. For additional interest, I’ve added the data for net goals scored per game at home – as expected there is high correlation between goals scored and points.
Let’s start with the most popular league in the world – the English Premier League. Here the trend is not dramatic but it exists. Since the 2011/12 season, the advantage has hovered consistently around 0.4 points per game albeit with a slight dip to 0.32 pts/game in 2015/16 and a spike to 0.61 pts/game the following year. In the earlier years of the Premier League, the advantage was generally between 0.5 pts/game and 0.7 points/game, rising to an all-time advantage of 0.8 points/game in 2009/10 before falling to the current range two seasons later. The correlation between net goals scored and net points is 86%.
When we look at the German Bundesliga, the downward trend of home field advantage is much more obvious. Seasons in the past decade and a half have yo-yo’ed between 0.4 and 0.6 pts/game with a few dips below the 0.4 pts/game threshold – indicating more parity. But prior to 2005/06, home field advantage was much greater. In the the 1970s, playing at home provided at least one additional point per game on average and throughout the 1980s and 1990s a dip below 0.6 pts/game was an anomaly. Here the correlation between net goals scored and net points is 96%.
The Turkish Super Lig has a similar trend as the German Bundesliga. The turn of the millennium saw the advantage of playing at home stabilize to a lower level than in previous decades though there is a bit more volatility in the differences in Turkey. The second half of the 1970s into the early 1980s provided a dramatic advantage for home teams, peaking at a remarkable 1.44 pts/game advantage in 1978/79. The correlation between net goals scored and net points is 90%.
So that’s a macro view of home field advantage for different leagues across several seasons. But what about individual teams? Which clubs had the greatest disparity in their performance at home versus their travels?
In my data set, the team with the greatest net advantage was Turkish side Orduspor in 1983/84 earning a remarkable 2.29 more pts/game at home. Their home record was second best in the league that year but they tallied 15 losses and two draws and not a single victory in 17 journeys to opposition venues. So that’s 41 points at home… and two away. Here are the top three teams for each league in terms of net home advantage. I’ve also included the least effective at home, or, to view their performances more positively, the best travelers.
| League | Season | Team | Points at Home | Points Away | Net Points/Game at Home |
|---|---|---|---|---|---|
| Türkiye Süper Lig | 1983/84 | Orduspor | 41 | 2 | 2.2941 |
| Türkiye Süper Lig | 1971/72 | Giresunspor | 36 | 2 | 2.2667 |
| Türkiye Süper Lig | 1978/79 | Diyarbakirspor | 38 | 7 | 2.0667 |
| Türkiye Süper Lig | 1992/93 | Fenerbahçe | 24 | 34 | -0.6667 |
| German Bundesliga | 1974/75 | Bochum | 42 | 5 | 2.1765 |
| German Bundesliga | 1967/68 | Borussia Dortmund | 39 | 4 | 2.0588 |
| German Bundesliga | 1971/72 | Eintracht Frankfurt | 45 | 10 | 2.0588 |
| German Bundesliga | 2015/16 | Darmstadt 98 | 12 | 26 | -0.8235 |
| Premier League | 2005/06 | Fulham | 41 | 7 | 1.7895 |
| Premier League | 1992/93 | Leeds United | 44 | 7 | 1.7619 |
| Premier League | 2017/18 | Arsenal | 47 | 16 | 1.6316 |
| Premier League | 1997/98 | Crystal Palace | 11 | 22 | -0.5789 |
| Spanish La Liga | 2015/16 | Sevilla | 43 | 9 | 1.7895 |
| Spanish La Liga | 2012/13 | Sevilla | 40 | 10 | 1.5789 |
| Spanish La Liga | 2016/17 | Las Palmas | 33 | 6 | 1.4211 |
| Spanish La Liga | 2018/19 | Girona | 15 | 22 | -0.3684 |
A metric like pts/game is useful to gauge advantage but sometimes you just want to look at win-loss records. The results will mirror what is reviewed above but it’s helpful to see some findings in the format we’re used to regularly tracking in a league table. The full season-by-season records are included in the file attached at the end but here are some highlights.
In the Premier League, two seasons stand out for particularly woeful – relative to other season at least – experiences for home fans.
1993/94: 192 wins, 142 draws, 128 losses for a win percentage of 41.6%.
And over twenty years later, the Premier League so its lowest home win percentage.
2015/16: 157 wins, 107 draws, 116 losses for a win percentage of 41.3%.
Meanwhile, fans got their money’s worth out of a trip to the park in two seasons where home teams won over half of their games, though by a fraction of a percentage point. It’s just fascinating to me how difficult it is to win a game in football.
2005/06: 192 wins, 77 draws, 111 losses for a win percentage of 50.5%
2009/10: 193 wins, 96 draws, 91 losses for a win percentage of 50.8%
But it was German fans in the 1970’s who saw the most joy watching their teams in person. Three times did the Bundesliga crack the 60% win percentage barrier:
1979/80: 184 wins, 63 draws, 59 losses for a win percentage of 60.1%
1972/73: 187 wins, 67 draws, 52 losses for a win percentage of 61.1%
1977/78: 191 wins, 60 draws, 55 losses for a win percentage of 62.4%
These seasons are a far cry from the glory years for away fans when home teams in Germany won only 40.2% of their matches in 1990/91 and 1995/96.
Here are the aggregate win-draw-loss records for all of the seasons for each league. Wins for home teams have been more frequent in Germany than in the other leagues.
| League | Seasons | Wins | Draws | Losses | Win Percentage |
|---|---|---|---|---|---|
| German Bundesliga | 56 | 8667 | 4387 | 4024 | 50.7% |
| English Premier League | 27 | 4856 | 2747 | 2903 | 46.2% |
| Turkish Super Lig | 60 | 8409 | 4868 | 3947 | 48.8% |
So that’s overall team performance. But what about other ways that home teams may gain an advantage. One wonders, for example, is it true that the home team generally gets the calls? The short answer is yes, yes, they do. But as is the case with overall performance, the home field advantage in influencing the referee (to take one perspective) or cowing the opponents into fouling and conceding penalties (to take another) has diminished over time. But it certainly exists.
Let’s take a look first at penalties.Unfortunately, I don’t have data for penalties given but only penalties scored. It’s probably a good enough proxy given penalties have high conversion rates. Still, I would have loved to explore whether penalty conversion rates differed between home and away teams.
In the Premier League, you can immediately see that home teams score (and, presumably, win) more penalties. The proportion is typically over 60% with several seasons exceeding the 70% mark. Only a couple of seasons – 2001/02 and 2018/19 are at about the 50/50 level. There really isn’t any sort of trend though it’s worth noting that last time home teams had 70% of penalties was a decade ago.
The Bundesliga shows similar results though here there is a more evident trend towards a smaller proportion – but still significantly over 50% – of penalties scored by home sides in the past decade or so. It could very well be that English football would show a similar trend if I had data predating the formation of the Premier League. It’s worth calling out the aberration that is 2005/06 where only 40% of penalties were scored by home teams. It’s a statistical outlier and it’s hard to know if there was a refereeing impact or if home sides were just considerably worse at converting their opportunities.
And, finally, we take a look at Turkish football, which has some interesting trends. First, as we already saw in the results analysis, the 1970s and 1980s were halcyon days for home teams. Three times the proportion of penalties scored by home sides exceeded 80% and twice they just about approached that mark. Recent years have continued to be favorable for home sides but oddly the 70% mark, which is somewhat common in English and German football, was last exceeded over 30 years ago. Like in the German football chart, there is a single anomaly in the distribution with the 1992/1993 season dipping almost to 40%.
So we see that the assumption of bias toward home sides for penalty decision is grounded in reality. What about bookings? For this analysis I also included dismissals to see if there were any curious trends. In the graphs below, bookings are all yellows and reds, while dismissals include both straight red cards and second yellows.
Surprise, surprise: home sides receive fewer bookings. But a trend toward equal card distribution is evident and it’s hard to really say there is an appreciable advantage for home teams in recent years as there was at the beginning of the Premier League. Meanwhile, the data on dismissals is all over the place – to be expected given the much smaller number of red cards as compared to yellows and hence more likelihood of volatility from season to season. It’s interesting to see several seasons where home teams were just as likely to have players sent off as their opponents – is it the energy of the fans leading some to go too far into a red mist, or perhaps home team players are more likely to lash out while in losing positions due to pressure from their supporters.
Having data from several decades of German football shows a more marked trend toward equal card distribution. But interestingly, German football seems just a few percentage points farther from 50% than English football in recent years. You can see the upward trend of dismissals as well despite what looks to be some unfortunate noise in the early part of the distribution surely caused by poor data.
Turkish football shows an interesting trend – it is upward toward equality as in German and English football but it reached a leveling off near equal distribution much sooner than the other leagues. This is the same trend we saw in the penalties chart. It’s somewhat odd, at least to me, given how much press time is spent in Turkey bemoaning refereeing advantages. But perhaps the explanation is that Turkish football has fewer big clubs, where I define big in this context to mean large stadiums filled to the brim with fans. Sparsely populated stands certainly ease the pressure on referees and away sides but it’s still peculiar given the significant performance advantage we see in the charts at the top of the post.
Finally, for odds and ends and because I had the data, I decided to take a look at own goals and substitutions. I won’t provide an analysis for each chart but some general observations are in order. Own goals are pretty much randomly distributed. I had hypothesized that perhaps own goals scored by home sides (which is the same as saying own goals scored on behalf of home sides) would be consistently greater given a greater attacking impetus. However, the low volume of own goals instead displays volatility and no real pattern emerges.
Meanwhile, substitution patterns have little to do with where a match is played though there are a few seasons here and there that diverge significantly (albeit in relative and not absolute terms) from an expected 50/50 distribution. There is a broader trend in the early years of the Bundesliga and Super Lig of more substitutions by home teams. I’m reluctant to draw any conclusions as I wonder if there are biases in the data set. It’s still peculiar as one might be inclined to think that visiting teams, whether because they are more likely to be fatigued or chasing a game, would substitute more.
You can find a full data set here. That’s a direct link to download an excel document that I created to play around with the data and build the charts. I have a separate database of match and event data for all of the leagues. Feel free to explore some of that data and different visualizations on my football site: dorukakan.com/football/football.php.