When two English football clubs met in the Champions League final in Moscow last May, the International Herald Tribune wrote of "apocalyptic predictions that a volatile mix of boozy British fans and club-happy riot police will spark chaos on the streets".
That this chaos never emerged during the match between Chelsea and Manchester United was the result of a massive co-ordinated effort by British and Russian authorities - and the insights of a psychology lecturer at the University of Liverpool.
Clifford Stott's research, which discovered that aggressive policing sparks rather than subdues riots, is the basis of a new training programme for officers policing football matches across Europe.
Football and disorder
Dr Stott began studying football for his PhD on the social and psychological dynamics of riots, under the supervision of Steve Reicher, then at the University of Exeter and today professor of social psychology and head of the School of Psychology at the University of St Andrews.
"It was a difficult question to address empirically," Dr Stott said. "I started going to football matches as they are more predictable - they're at set times and locations, and you can be relatively confident that in the process you will witness disorder."
His "breakthrough" came in 1990 when, having witnessed the poll tax riots and disturbances during the football World Cup finals in Italy, he realised that in both cases the violence was linked to the way the crowds had been policed.
Professor Reicher's research on riots in Bristol a decade earlier had challenged the view popularised by French social psychologist Gustave Le Bon that crowds are dangerous, irrational and prone to disorder.
He showed that crowds behave rationally and public protests do not inevitably descend into violence. Dr Stott's analysis of the poll tax riots showed that disorder had erupted after baton-wielding police charged peaceful protesters. They then united in opposition to what they saw as unfair treatment.
Dr Stott's interviews with riot police confirmed that their tactic was to use force indiscriminately in response to minor incidents, suggesting the influence of Le Bon's theories of crowd behaviour.
While the British police were initially sceptical about the lecturer's work, he obtained funding from the Home Office to study the interaction between police and fans at international football matches in collaboration with Dutch police.
He got in touch with the Portuguese authorities before the European Championship in 2004, and his research was used by Portugal's Public Security Police (PSP), one of the country's police forces, to develop a strategy for the event.
"We suggested that rather than wheeling out the riot squad in a great show of force when the police first meet the crowd, they should wear normal uniforms, move in pairs or small groups and interact with (it)," Dr Stott said.
"This creates a sense of legitimacy. People feel as though they're being policed appropriately, and it allows police to identify those who are likely to be a threat."
Force is then targeted at the troublemakers rather than the whole crowd. The majority, recognising that those arrested have done something wrong, keep quiet or even help to maintain order.
The Guarda Nacional Republicana (GNR), another Portuguese force in charge of policing matches at Euro 2004, decided against collaborating with Dr Stott's team and used traditional methods.
Thanks to funding from the Economic and Social Research Council, Dr Stott and his team gathered data on confrontations during the tournament, and found that two riots occurred at matches in the GNR's jurisdiction, compared with none in the areas overseen by the PSP.
Europe-wide training programme
The following year, recommendations based on Dr Stott's research were included in a European Union handbook on controlling violence at international football matches.
He is now helping to set up a pan-European police training programme on match safety. The second phase of the project, for which an application for EUR8 million (£7.1 million) in EU funding will be submitted in July, will see the programme implemented across the Continent.
Dr Stott believes that his findings have implications beyond the policing of sporting fixtures.
"One of the consequences of the PSP's policing style was that it created an identification between the police and what had been a marginalised, antagonistic community, to the point where the English fans began to self-police.
"You can translate that into a model of community policing with other marginalised groups - the Muslim community, for example."
Despite the clear practical benefits of his study, Dr Stott said that research funding had been difficult to come by. "My work is not readily recognised as valuable at a scientific level. It's very difficult to get published in high-impact journals if you're doing research based on qualitative field observations."
While the Euro 2004 study did produce quantifiable data, it was "a massive struggle" to get it published, he said. During the championship, he remembers a man stepping in front of a group of fans to stop them attacking the police. "He said: 'We're English. Where's your pride?' Our research suggests that his behaviour had a widespread impact. But how do you quantify that?"