Well...wat u nid to do is give the first strike which will make him or her pain as much as possible...because the pain will make them annoyed n they cant concentrate to hit u back...they will defend as much as possible...and it will make u to win the spar easily...im not pro but tis was told by a martial arts instructor in discovery channel...make spar as a sport...dun be too angry when u have been hit because anger can make u react slowly and inaccurately...remember..points will be given if u hit the target accurately...not by hitting the air...

all the best to u guys...sorry if im wrong...