An excellent strategy against a Kick-Boxer is to fell him after his kicks

Using Stances and Body-Movement to Counter Attacks

When an opponent attacks, instead of retreating you can use your body-movement or shift into a False-Leg Stance to avoid his attacks. Then close him following his attacking momentum. This closure of the opponent to prevent him from further attack is very important. Swiftly move in to fell him. Notice that you can also effectively fell him by stepping on his leg.