Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency.
Table tennis
Adding spin onto the ball causes major changes in table tennis gameplay. Although nearly every stroke or serve creates some kind of spin, understanding the individual types of spin allows players to defend against and use different spins effectively.