If I had to rate my self, I would rate myself a 3.5 player. I didn't know much about strings before, so I used the wilson sensation 17s...boy was that a mistake. I use the wilson kblade 98. My first serve is about 65 mph (Ive only been playing two years so I can't serve fast yet) and my ground strokes are about 45-60 mph. I don't volley often, and I only slice if the ball is too low of if i can't reach it in time. I need a string that does offer power and some control to match the added power. I don't break my strings easily.