With this paper and the communication that will be presented, I will produce the results of an investigation about four Ultra groups that support the top three football clubs of Oporto, known in Portugal as claques. I intend to state the main reasons that allow me to consider the Leicester Group theory the best in order to understand the hooliganism and delinquent behaviour of some members of Ultra groups in Oporto. The main points of the theory will be compared with the corresponding empirical data that confirms it. There are 47 neighbourhoods in Oporto, which makes it the Portuguese city with the greatest number of these neighbourhoods. More than 20,000 people - 20% of the population of Oporto - live in this type of well-identified territory in urban space. Quantitative and qualitative data, obtained through participant observation, interviews, life stories and inquiry by questionnaire, reveal the presence of a social configuration that the Leicester Group proposes in order to explain football hooliganism. This data also allows me to confirm that delinquent behaviour and some violence that could be observed in a football context can be seen as a social reproduction of a delinquent course already present in everyday life. The limitations of the Leicester Group theory will also be considered. This investigation has found that these supporters have a strong sense of belonging to their community and to their city, which is also symbolically reproduced in football stadiums. Finally, I will propose the concept of social experience as an adequate concept to study this kind of social phenomenon.