Each person’s action affects everybody. This fine principle of teamwork applies even when individuals are pulling in different directions. Trying both to reach the chocolate box in one’s nearest corner and to stop the others reaching theirs, resistance becomes momentum and then desperate resistance again. Progress is most effective backwards. The square of rope comes alive, morphing into a diamond, a triangle, a trapeze, as the advantage shifts with every second. It’s when you’re nearly there that you’re most vulnerable, losing impetus, to grab the prize or be dragged back. The balance of forces is always broken in the end.