In soccer and other sports, we often hear about the home field advantage. Anecdotally, most athletes and commentators will tell you that it’s easier to win a match at your home ground than away at a different team’s ground (Wikipedia).

I’m curious about whether this trend actually holds if you scrutinise the data.

The A-League Women (Australia’s top competition in women’s soccer) recently finished the regular season. In this tournament, there were 12 teams, and each team played one home match and one away match against each other team.

Using a spreadsheet to perform some quick manipulation of the final league table (available from Wikipedia), I’ve arrived at these key facts:

  • Across the season, there were 222 goals scored by teams playing at home. In contrast, there were only 183 goals scored by teams playing away from home.
  • This means that, across all 132 matches, home teams scored an average of 1.68 goals per match. Away teams scored an average of 1.39 goals per match. This also means that there is a +0.29 average goal difference in favour of the home team.
  • In terms of match results, the home team won 67 matches and the away team won 41 matches. There were 24 draws. This means that matches were won by the home team 51% of the time, won by the home team 31% of the time, and drawn 18% of the time.

That last finding means that, for a team playing at home, they are about twice as likely to win or draw as they are to lose.

Neat!

I have a hypothesis that the home advantage will be less noticeable in very casual soccer leagues. In the casual/community league in which I play, there seem to be different dynamics at play; it’s common to see results like 9-1 and 16-0 (both of which we’ve already seen in the league even in the first few weeks), whereas these results are very rare in the A-League.

I suspect that, since professional or semi-professional leagues are already doing a good job of optimising for performance (picking the best players, training them effectively, and adopting a mindset that winning soccer matches is the #1 priority), factors such as the home advantage that give a team a slight edge are more likely to be decisive. In contrast, in casual/community leagues, there is far more variance in skill level, experience, dedication to the sport, and mindset (winning vs having fun). I suspect that this variance would essentially drown out any home advantage. I’ll have to wait until my league’s season is over and analyse the results!