A bull has the ability to charge at you at up to 35mph. There are 1040 possible moves in chess. If a cue ball hits half of the intended ball in snooker – and not the centre - the probability is very high that the cue ball will travel in a direction that is 30 degrees from the aiming line and in the opposite direction of the ball that was hit. Such calculations lie behind activities that humans over millennia have considered as “play”. Yet when we are involved in playing, we rarely have the time to make these types of estimations - we are immersed in an activity. It seems that these types of activities are inextricable from the human condition.