A whole lotta practice and a little bit of luck. I have never played the game in question. But I have played Call of Duty. I was looking for a perfect game for awhile (ie no deaths, about 30 kills or more). I knew it was possible because I saw other people do it. I practiced "quick scope" "no scope" "hard scope" everything I could think of. I found out the ideal class, guns, perks, everything. Then one day, I did it. I might as well have been playing by myself with no other clan members. I annihilated the other team single handedly (just don't ask me to do it again). I think you know what I mean, knowledge is power, and luck favors the well prepared. Hope this helps.