GearScore was designed to provide players with a way of viewing the overall power and potential performance of another player's equipment PlayerScore allows you to view the GearScore of any player either in-game or online.
PlayerScore will only measure the GearScore of equipment a player is actually wearing and will ignore all other items.
GearScore includes a much higher level of resolution, which allows the score to be much more accurate.
GearScore will go up or down depending on rather or not equipment is gemmed or enchanted. Gems and enchants will increase the performance of a player and should be included as bonuses to their equipment's GearScore.
GearScore will be severely reduced if a player equips equipment that is not designed for their class or spec. An example would be a warrior with Healing plate gear. The healing plate gear offers no increase in the warriors tanking or dps and so is not included in the player's total GearScore. PVP equipment will receive a penalty to a player's GearScore. This is because PVP gear is designed for short-term dps and survivability, and doesn't provide the same level of dps or sustainability required for boss fights as PVE gear does. Each item's GearScore is dependent not only on the item's rarity and item level, but also the type and location of the equipment. For example, a 2-handed weapon will receive a vastly superior GearScore compared with a belt or bracers. GearScore is color coded so your brain can spend less power on determining if a score is good or not, and more power dodging the fire on the ground.
To access GearScore you must use the PlayerScore addon or web service While not a direct benefit of GearScore, PlayerScore which provides GearScore comes with a slew of bonus features such as char act her experience; pvp, pve, and raid scores to provide a better picture of a player's history; talent, gem, and enchantment auditing; player ratings; and more!