Ever wonder why your strings are moving so much? Simple. They're supposed to. The more spin you hit, the more the strings should move, and the more they move, the more spin potential you will have. In this era of tennis where standing at the baseline and trading big groundstrokes, topspin has become more important. The more spin you can hit, the larger the margin of error over the net and shot depth. String movement helps increase spin potential. When strings move more they can grab the ball, hold on longer and impart more spin. There are many factors that can add to the string movement. 1. "Spin patterns" - Companies like Wilson are making rackets with intentionally more open string patterns. This increases the space between strings, giving them more room to move to increase spin potential. (see video below) 2. Stiffer rackets - As rackets have gotten stiffer, players have found that they can hit the ball with more power. When a frame is stiffer, it doesn't give as much at impact. The only other thing that can give is the strings, and they will give more, and move more. This increases power and spin potential 3. The strings themselves - Many strings are made with a coating on them to increase the ability of the string to move across itself without wearing into itself. This adds some durability as well as spin potential. Something we see here is customers asking to have their rackets strung as tight as possible to reduce string movement. This only works to a point. Hit enough spin, they will still move, not to mention the increases shock at impact and loss of depth and power. Others will use a poly string because "they don't move". They still move, but the stiffness of them gives them more of a tendency to return to where they started. For many though, poly strings are tougher on the arm and require more effort to get the ball deep. We do have to be honest about one fact of string movement. More string movement does, for some players, reduce the life of the string. The friction at the intersections of the strings causes them to wear through and eventually break. Generally, the harder you hit and the more spin you hit, the quicker you're likely to have your strings break. The trick is to find a string and tension combination that maximizes spin, power and feel, without sacrificing durability. Yes, moving strings back is a pain, but the additional spin is more than worth it in the form of more balls hit in and points won. Check out the video below to see the effects of string movement on spin in the Wilson Spin Effect rackets.