In boxing and continuous fighting such as boxing, kickboxing and MMA the foil can be used widely in tying up an opponent so he cannot fight back effectively. In boxing I was taught to spoil which is the name my father (who taught me to box) used to refer to foil tactic.
An old tactic in boxing was to put something on ones gloves that would burn the opponents’ eyes so he couldn’t focus.
Others are the controlling and clinching to foil the opponent’s attempts to get off a clean punch. Muhammad Ali used the foil extensively to lift the Heavyweight title from George Foreman in one of the great fights we know today as ‘the Rumble in the Jungle’. This fight is a classic example of the foil in action. Muhammad Ali the consummate strategist completely nullified everything Foreman tried to do. Foreman was frustrated constantly; he couldn’t think straight or launch effective attacks as Ali, spoiled, intercepted, clinched, trapped and turned him.
If you want to study spoiling in action I highly recommend watching this fight.