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\section{Introduction}  State-of-the art methods on soccer match analysis use extra high level data and annotations (such as whoscored, transfertmark) which require human annotation and so preprocessing \cite{reillyscience}. \cite{reillyscience}, \href{http://pena.lt/y/2014/02/10/comparing-players-using-cluster-analysis/}{Comparing Players Using Cluster Analysis}.  In this project we limited our input to the video of a match, recorded with a multi-camera system. We focus on unsupervised classification of the players based on clustering of their trajectories, automatically extracted from match video sequences during a short period of time. Based on this information, we are interested on characterizing several aspects of the match (such as detecting the game leaders, to anticipate the displacement of the players or to find patterns in the player paths). In such a way, we aim at obtaining details about the team strategy through the analysis of high level semantic cues. The problem of tracking players with multiple cameras has been consistently studied, for example in \cite{Ben_Shitrit_2011} even if their paths may intersect over long periods of time. In this studies, the clustering process is closely linked to the choice of a metric explaining the similarities among the objects we want to classify: in our case, the player trajectories. Most of the time the metrics used are based on euclidian distance \cite{jain1999data}. However, only discrete trajectories are available in the form of array which can be of different sizes, with different time discretization or with different speed. Euclidian distance would not result in a good choice for these cases. So, in our case, a relevant clustering process should be decomposed into 2 parts:  \begin{itemize}