Resumen

Owing the importance that off-side now has (understood as a defensive tactical measure) and its high frequency of use in top level teams, we have brought into practice a descriptive study of this type of situation during the European National Cup in England in 1996. Through videos and the later analysis of the pictures of the matches, we have found a series of error at a defensive level- in their realisation, which could be important indications in the work of this tactical medium.
The first step in the investigation consisted in the creation of an observation pattern where all those aspects of motor conducts that we wanted to observe were shown. From the determination of this series of study variables and their
corresponding categorisation, we found abundant information about off-side which ratified our hypothesis that too many and important mistakes were made.
Through this study, apart from ratifying this aspect, we have been able to conveniently structure the work, which could serve as a guide and also help the work of both trainers and players. By means of this method, based on the observation of audio-visual material with a slow camera, we have been able to extract a series of basic conclusions so as to nderstand and undertake the contents of this work