In the world of sport, it is a generally accepted view that a team, or player, competing on home turf should have some kind of advantage over their opposition. This concept is so ingrained into the sporting institutions of the world that pretty much every sports league in the world has some kind of mechanism whereby teams play each other both home and away over the course of the season, so as to “balance out” the effect.
But if one thinks about it more deeply for a moment, it appears to be a strange concept. What is it about, say, Anfield that makes Manchester United less likely to beat Liverpool there than in the same game played at Old Trafford? The pitch is, give or take a few feet, the same size, the rules are the same, there is no intrinsic difference between the two settings. And yet, of the last 32 games between the two sides which have resulted in a win, 19 were won by the home side. What’s going on here?
In some sports, the difference is intrinsic. For example, in cricket, the pitch itself has a massive effect on the result of the game. For example, Australia is known for fast, bouncy pitches which favour fast bowling, while the Indian subcontinent is known for slow, dusty pitches which turn prodigiously. It is little wonder, therefore, that Australia has won only won one test series in India since 1969, given that the Australian players would have grown up playing in conditions markedly different to those they faced in the subcontinent.
But as we have already established, such effects do not exist in most sports. So where do we turn? The most commonly cited reason is that of the crowd under the guise of a psychological effect known as social facilitation. This was examined in detail in 1965 by Robert Zajonc, who concluded that learned, repetitive tasks such as instinctive plays in a game, are performed better while in the presence of an audience. This was backed up in a sporting context in a 2003 study by Rhea, Landers, Alvar and Arent, in which it was found that an audience increased the maximum weight the participants in the study were able to lift. Combined with the support that a home crowd provides their players, one could see why such an effect could encourage a home side better.
And yet, once again, this is not backed up by statistics. Richard Pollard, a statistician from California, published Long-term trends in home advantage in professional team sports in North America and England (1876 – 2003) in 2005, a statistical analysis of home advantage across numerous sports, including football, baseball, ice hockey, basketball and American football. To do this, he calculated a quantity, which he conveniently called home advantage, which he defined as the percentage of total points awarded that went to the home side throughout each season. His findings for the English first division, which became the Premier League in 1992, over the period of the 1973-74 season to the 2002-03 season, are shown in figure 1. As one might expect, the exact value of the home advantage quantity varies considerably from season to season, ranging from a maximum of 68.7 per cent in the 1982-83 season to a minimum of 56.7 per cent in the 1988-89 season. Over this period, home advantage, on average, was about 62 per cent. This confirms that there is indeed a statistical backing to the idea of home advantage, at least in football, but, more interestingly, if one then compares this data with that shown in figure 2, which is the average home league attendance for each season of the English first division over the same period, it is apparent that there is very little correlation between the two sets of data. Indeed, the average league attendance grew significantly between the 1992-93 season to the end of the period examined, while home advantage continued its slow decline which it had shown across the entire period. This is unexpected. Surely, if the crowd has such an effect on the performance of the players, a bigger crowd would have more of an effect.
This might lead one to conclude that the crowd is not the driving factor in the phenomenon of home advantage. Pollard, for one, claims that his evidence suggests that a home crowd has little effect on home advantage, citing the data above as part of the reasoning, as well as the decline in home advantage being greater in sports such as ice hockey, in which the crowd are very noisy and close to the players.
On the other hand, the decline in home advantage might not be due to the lack of a crowd effect, rather that the increase in performance due to a larger crowd might be being washed out by an increase in performance of the away team due to improvements in facilities and transportation. This would lead to a decrease in the effect of other supposed contributing factors to home advantage: familiarity with the surroundings and travel fatigue.
Back in the early days of professional sport, before the amount of money in the game was quite so mind-boggling, the facilities might vary significantly between stadia. The homogeny of today’s professional football pitches was impossible, especially in a sport such as ice hockey where the pitch quality depended on the care for something so fickle is ice. Thus, a side which played week in, week out on a pitch was far more likely to learn the individual foibles of the surface, and be able to use them to their advantage against visitors less familiar to their surroundings. Similarly, today’s sportspeople travel in luxury well in advance of a fixture, meaning they will be far better prepared than past sides whose travel was far less comfortable and often much lengthier in the days before flying was easily accessible. This would explain the decline in home advantage over time, since these effects would be far less powerful nowadays when the variation between playing surfaces are minute, and the effects of travel are negligible.
The continued existence of a crowd effect is borne out by its adverse effect on individual athletes playing at home, where the weight of expectation often outweighs any benefit the crowd might have on their performance. This is again shown in Pollard’s statistics, which show that of all sports analysed, baseball was the one which showed the smallest home advantage. Baseball is uniquely individual among the sports studied. Only the pitcher and the batter can influence the setup of play, the actions of fielders and runners is reactionary. This, combined with baseball’s seeming obsession with individual statistics, means that the expectation of the crowd often falls onto individual players. As such, the natural human instinct to avoid embarrassment kicks in, leading to greater pressure on the player and meaning that he is less likely to perform to the best of his ability.
Overall, I think that there is a psychological element to home advantage. Humans are herd animals, we enjoy being in like-minded groups, and as any high school clique demonstrates, we will often go to great lengths to maintain the good favour of any groups we might be part of. Thus, the support, or otherwise, of a large group of people must surely have an effect on the confidence of players and, as a consequence, their performance. I do not believe, however, that this is the dominant factor which causes the phenomenon, since, if this was the case, we would see correlation between attendance and home advantage, something which is not borne out in the statistics. Rather, the factors which affect the performance of the visiting side, namely familiarity and travel fatigue, are more powerful than the crowd effect, resulting in the decline of home advantage as modern sport has moved towards homogeneity.