well before a game i put on a brand new grip, and then in the middle of the game, my hand were slipping of. so i was wondering if theres anything i could do with that. Kevin.
Grips must have friction or else they lose power. Avoid smooth surface grips that don't give you friction. A lot of overgrips have smooth surfaces, and if so they are useless. However, if you sweat a lot and you play in a hot and humid environment, then towel grips are best.
All the previous suggestions are valid. The best option is using towel grip in combination with chalk. However, if you have strong preference towards smooth grips, then there are two partial remedies I can think of. The first option is to build up the butt cap area. This is done by cutting stips of grip and overlapping them only on the plastic butt cap area. The second option is to half overlap the grips. This will make a smooth surfaced grip rougher.
Making the butt cap larger but still using smooth, frictionless overgrips is still not good enough. Power is lost through lack of friction. The larger butt does nothing but just stop your racquet from slipping away.