ABSTRACT
Performance in ball games is much more difficult to appraise than it is in individual sports. In track-and-field athletics the competitor who passes the winning post first, jumps highest or longest, or throws the missile furthest becomes victorious. All competitors can be judged according to their finishing position, or on the time taken or distance achieved during performance. These kinds of metrics apply also to swimming, rowing, cycling, skiing and other events. In ball games the contest is decided by points or sets won, or goals scored. In soccer there is a simple determinant of victory: winning means scoring more goals than the opposition!
