I like Jimbos method too but we have been using Cold Storage on Pitch Black Mode. The mercs spawn a few feet from the middle hole so Riddick just stands down there and carves away as they drop down. 2-4 people and it just flys by. We each go to 99 points and when everyones done, end the game. At the next screen we all ready up (player match) and bam up pops the next game. Rinse and repeat.