The frequently used indicator in team sports is the player’s activity on the field during the game. The application of „Activity in the Game” serves to measure this time. We can measure the players’ activities during “pure” playing time depending on the terms applied in the given team sports. The query is possible for individual players of the given matches or aggregated; for a given match (all players entered for the competition) or for seasons (summary of the matches). Presumption from these data is solely objective of course, and it either helps the trainer to assess the player’s stamina in matches or contributes to the player’s assessment. However, the subjective factor cannot be omitted from the procedure of assessment either. The two factors together are suitable for real evaluation.