TENNIS.com gear editor Justin diFeliciantonio and his technical advisers answer your equipment questions each day. Click here to send in a question of your own.
I frequently hear commentators on TV speaking about how players tweak their tensions depending on the temperature, but I’ve never fully understood the logic behind it. Are you supposed to tighten or loosen strings when it’s hot outside? What about when it’s cold? Why do players do this?—Kerry U.
Good question, Kerry. Typically, players tighten their tensions slightly as the temperature rises and loosen it as it drops, respectively decreasing and increasing, in crude terms, the amount of power in the stringbed.
(More technically, changing tension affects the amount of energy and elevation the stringbed imparts to the ball upon impact. Generally, higher/lower tensions decrease/increase how much energy and elevation that stringbed imparts, thus decreasing/increasing the ball’s depth and speed.)
Question: Why do they do this?
Answer: In order to compensate (i.e., maintain their shots’ power and control) for how temperature affects the ball’s flight through the air. In hotter, drier weather, balls tend to play livelier, bouncing higher and moving faster as its rubber shell warms into a suppler, more responsive state. When it’s damp and cold, the opposite is true: Balls stiffen and return less energy upon impact, and thus play with less bounce and speed.
Indeed, to be able to smack the ball forcefully without hitting it out, players reason, it’s important that one’s tension isn’t too high in the cold or too low when it’s hot out. Granted, most temperature-prompted tweaks in tension are very subtle—typically only two to four pounds either way, depending on the weather’s extremity. Even so, these types of adjustments can make a noticeable difference in a player’s performance (and/or psychology), especially at the upper levels of the game.