Go to "Multiplayer", then "Public Match" and create your own game. Set the maximum number of players to 14 and reserved slots to 13, then set the game to first 5 out of 9. Place bot players on the opposite team and be the only player on yours. Begin a match on the Buffalo Field. Eliminate as many players as possible, then let the final person shoot you. When they have won four, stay put and win the last five by taking out all the players. Rush straight to the right and the opposite team will line up on the opposite end. Continue shooting them and making new games with the same rules until you get the achievement.