Strings (tennis)
The material used in tennis string can significantly affect a player's performance, and even health. Several materials are used to make tennis strings. They vary in terms of elasticity, durability, rebound efficiency, tension holding capability, and manufacturing cost, among other considerations.
Tennis scoring system
The alternation of service between games continues throughout the match without regard to sets, but the ends are changed after each odd game within a set (including the last game). If, for example, the second set of a match ends with the score at 6–3, 1–6, the ends are changed as the last game played was the 7th (odd) game of the set and in spite of it being the 16th (even) game of the match. Even when a set ends with an odd game, ends are again changed after the first game of the following set. A tiebreaker game is treated as a single game for the purposes of this alternation. Since tiebreakers always result in a score of 7–6, there is always a court change after the tiebreaker.