Bundesliga’s quiet return hints at a silent threat to home advantage | Sean Ingle | Football

So this is what football looks like for the foreseeable future. No handshakes, spitting, or fans. Balls doused in disinfectant before kick-off. Masked substitutes physically distancing in stands. Mandatory temperature checks for the lucky few allowed into stadiums. The game sealed off and sanitised, as if in the midst of a science experiment. All that is missing is hazmat suits.

But watching the Bundesliga’s return there was a vague sense of something else: that the action itself was also not the same without supporters cajoling, haranguing and singing hosannas. On social media some reckoned the games were more like pre-season friendlies, slower and less intense. Others – such as the Borussia Dortmund coach, Lucien Favre – hinted that the lack of atmosphere had disturbed a familiar equilibrium. “There’s no noise, you create a chance, you play a top pass, a goal and … nothing. It’s very, very weird,” he said after the 4-0 victory against Schalke. “We miss our fans very much. It was just a very different match.”

But just how different is football behind closed doors? That is a journey into the relative unknown.

Of course six Bundesliga games is hardly enough to reach any conclusions. Nonetheless, Opta’s data shows some intriguing differences in Saturday’s matches compared with those before the lockdown – including fewer 50/50 duels between players (an average of 60.7 compared with 71 before the league was suspended). There were also fewer touches in the opponents’ box (35.5 on average compared to 44.9 before the break) and more passes in each game on average (940 compared with 906), which perhaps hints that players were a little more cautious.

More games – and player tracking data – should provide a clearer picture in the coming months. But, regardless, there is another interesting element to Opta’s data which has to do with referees that can be expected to persist.

In the 224 Bundesliga games this season before the lockdown, referees awarded 151 more fouls against away teams and handed out 62 more yellow cards. On Saturday, however, that discrepancy vanished. Indeed, slightly more fouls and yellow cards were awarded against the home teams on average.

We should expect this. As Ignacio Palacios-Huerta, who sat on the board of Athletic Bilbao from 2011 to 2018 and is also a professor of management, economics and strategy at the London School of Economics, points out, referees are unconsciously influenced by crowds.

He and his fellow academics were the first to study how officials were affected by social pressure by looking at stoppage time in La Liga matches. Strikingly they found that when a home team was ahead by a single goal, the referee allowed almost 30% less additional time than average. However, if the home team was behind by one goal the referee allowed 35% more time than average. What’s more, when crowds were larger, the referees become more biased.

There was something else too. When the visiting team scored after the end of the regulation 90 minutes, stoppage time went on 15% longer than when the home team scored. In other words, referees were quicker to end the game if the home team scores, thus giving the visitors less time to respond, than if the visitors score.

In Spain, two teams particularly benefit from refereeing bias – Barcelona and Real Madrid. Though as Palacios-Huerta dryly notes, “most fans would not need an econometric regression to confirm this”.

A subsequent study looked at what happened in Serie A in 2007 after several Italian clubs were forced to play behind closed doors following the death of a policeman in the Derby di Sicilia between Catania and Palermo. Again the results were significant. The authors found that the typical home advantage in terms of fouls, yellow cards and red cards awarded against the away side all declined dramatically – and that the same referee behaved very differently when officiating the same teams in the same stadium if there was no crowd.

Notably, however, the researchers also found there was “no indication that the players are differently affected in games with and without spectators”.

Another fascinating piece of research examined how 40 qualified referees judged 47 incidents from a match between Liverpool v Leicester. Half watched with crowd noise, while another group watched the action in silence. Those viewing the footage with noise awarded significantly fewer fouls (15.5%) against the home team compared with those watching in silence.

Psychologists call this influence conformity. And you can see how it happens. If 70,000 fans are going to scream at you if you give a decision against their team, it can make referees subconsciously decide to keep the crowd off their backs.

So it comes as no surprise that video evidence has helped reduce home advantage. Before the NFL brought in instant replays, for instance, home teams won 59.6% of matches. Afterwards it dropped to 55.6%. Last season it fell to 51.7% – the lowest mark since 1972. Meanwhile in Europe’s top five football leagues, home advantage has fallen from 49% to around 45% – probably because of a combination of better referees, video replays and less hostile crowds.

Who knows how much further it will fall if sport is forced to continue behind closed doors until a vaccine is found? Either way, we will all be part of an unwanted clinical experiment into just how strange football is without fans – on and off the pitch – for the foreseeable future.