Yonex rates each of their strings in 5 different properties:

• Repulsion Power
• Durability
• Hitting Sound
• Shock Absorption Shock Absorption
• Control (Control)

Repulsion Power indicates the extent to which the string assists in pushing the shuttle out on contact. The higher the repulsion power, the greater the force you can generate with the string when you hit the shuttle. This is due to a trampoline effect that occurs when the shuttle makes contact with the string bed and is then bounced forward.

Repulsive power typically has an inverse correlation with string durability, as high repellency strings tend to be thinner and thus break more easily. Players should be aware that repulsion force is also inversely proportional to string tension. This means that a lower string tension results in a higher repulsion force.

An inverse correlation is a relationship between 2 variables moving in opposite directions. For example, because repellency and durability are inversely related, an increase in repellency will result in a decrease in durability.

Sustainability indicates the resilience of the strings against wear, pressure and damage. It is normal for strings to wear out after repeated use due to the strings rubbing against each other as they hit the shuttle. The time it takes for the string to break depends on the thickness and material of your strings. Usually, the thinner the string, the faster it breaks with repeated use.

hitting sound indicates how much noise is made when a shuttle is hit. This helps players gauge whether or not they are hitting the shuttle correctly at the sweet spot. If the sound is clear and clean, it indicates that the shuttle has been hit correctly, while a muffled sound indicates a miss hit. The higher the Hitting Sound value, the easier it is to hear the difference between clean hits and hits with a hit point outside the sweet spot.

Shock absorption indicates how well the string handles the force of a shuttle hitting your racket. When the shuttle hits the string bed of a racket, the string and racket will vibrate to absorb the shocks of the shuttle. Any remaining vibrations are absorbed by the player's arm and body. This phenomenon causes a delay to the player as he/she has to recover from the shock. The better a string absorbs shock, the less vibrations are transferred to the player and the faster the player can subsequently recover from the shock.

Control indicates the extent to which a player can influence the flight of the shuttle when making a stroke. Control is generally inversely related to repulsion power, as a reduction in the trampoline effect allows players to hit with greater accuracy and precision. The string has longer contact with the string bed and can thus be pushed in the right direction.