of course they use spin but much less than nadal does. if you just compare shots made by nadal and djokovich, djokers are faster and flatter and nadals travel higher over the net and then drop and bounce off higher. i didnt mean to say pros use no spin. some may even use a lot. but there is a point where it makes more sense, at least in certain situations, to trade off spin for more power, thus leaving your opponent less time to react.