This is a 4 controller, dual box boosting method (likely two friends who have two controllers each) to get the following achievements.
Don't You Die On Me
Don't Hate The Player
Level 5
Level 10
Level 25
Re-Up
Seriously
CQC
Can't Touch Me
I Can See You
Set both systems up with split screen, and go to Versus.
Press Y and change both systems to a region like Japan.
Select Xbox Live, Competitive Match, 2v2 Gnasher Execution.
Count down from 3 and both press A at the same time. You should be joined together, if not keep trying until you are.
Alternate between who will win 6 rounds and who will get 7. For the person getting kills on your current round, just have them run straight over to the team losing that round.
The losing player should be moving his two characters side by side of each other. The person getting the kills will down one character then the other person will pick that one up. Do this twice for both characters, then the winning person will get the final kills on both.
The score board should look like this at the end.
https://onedrive.live.com/redir?resid=D5C89A67EB9C26AB!25063...Each match will take 10 minutes with all loading screens, and net 8125XP to the winner (after you have gotten the 10 consecutive game XP) and just over 6800XP to the loser. That is approximetly 15000XP each every 20 minutes for two players.
https://onedrive.live.com/redir?resid=D5C89A67EB9C26AB!25065...https://onedrive.live.com/redir?resid=D5C89A67EB9C26AB!25064...You can also finish off wins for "Can't Touch Me" and do spotted kills for "I Can See You" as well.