In one of the upcoming patches Riot plans to unveil a new scoring metric for games, temporarily being called "Escapes". They are unsure on how the exact details of this metric will be calculated yet but they plan to implement it as soon as they can because they don't feel Kills, Deaths, and Assists really tell the fully story of a game.

From a Riot Programmer speaking on condition of anonymity, "Too often during a game, in team fights, but especially in laning, sudden deaths are avoided because a player is able to maneuver away from a fight with less than 100 of their hp....
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