With the use of QTC (Qualitative Trajectory Calculus), the movements of the players are being converted to an internal data format. With QTC, interactions between players can be analysed in a qualitative way to reveal tactical patterns in the game.In this way,repeating movement patterns of players can be detected. A major advantage of this method is the strong reduction of data volume, wich makes it able to analyse tactical patterns in a large range of matches and even between different teams. The final goal is to support video analysts, coaches,.. etc. to measure, analyse and compare in an objective manner the team organisation, tactics,… etc. to those of competitors or their own matches from the past. In a first phase the research is conducted on football, volleybal and basketball but the technique can also be applied to various other sports.