  Big Data Analytics help team sports' managers in their decisions by
processing a number of different kind of data. With the advent of Information
Technologies, collecting, processing and storing big amounts of sport data in
different form became possible. A problem that often arises when using sport
data regards the need for automatic data cleaning procedures. In this paper we
develop a data cleaning procedure for basketball which is based on players'
trajectories. Starting from a data matrix that tracks the movements of the
players on the court at different moments in the game, we propose an algorithm
to automatically drop inactive moments making use of available sensor data. The
algorithm also divides the game into sorted actions and labels them as
offensive or defensive. The algorithm's parameters are validated using proper
robustness checks.
