Killstreak: A Call of Duty multiplayer timeline [Part 1]

Call of Duty 4: Modern Warfare had a profound influence on how first-person shooters would be designed, especially when it comes to multiplayer. With the recent reveal of Advanced Warfare's multiplayer features, we're following through history to see how COD's fast paced multiplayer became what it is, and what it will become. Part 1 covers Call of Duty 4: Modern Warfare to Black Ops.