My definition has little to do with kd. Its how the player moves around the map using lines of sight and cover, shooting with accuracy , and how the player performs in gunfights involving one on ones or with more than one enemy involved, how the player deals with it. Does he/she panic and shoot at everything on prioritize targets and take them out with careful shots and strategic use of grenades. KD I think does show some skill but I also understand that sometimes people what to have fun, mess around, and use not necessarily good but fun challenging guns.