Materials :
*3 Friends who will listen to you or know how to do this
*Caltrops
*MG
How to :
Step 1 - Go open a CF room and put the settings to extreme. Lock room and invite 3 friends who know how to do this (corner trick) or follow you correctly.
Step 2 - One start, place caltrops in center of the cabin, next to the pole in the middle of cabin fever. MAKE SURE YOU PLANT QUICKLY!
Step 3 - Run to the corner of where the gate is, where in round 16, the zombies come out from! Stay in the corner and do not move, or say a command. If you move a bit with a keyboard, or mouse, you fuck it up so run to the corner, crouch and make sure you guys are together no spaces apart.
Step 4 - all the zombies will not see you because the corner is a glitched area where the zombies cant see you so if you dont move, you should get around 20-50k play points in round 1.
Step 5 - After the zombies find you, run and shoot every one of them you will get like 60k Play Points top in the first round if you follow this.
Step 6 - do the same as step 1 and remember, make sure 2 people run the corner crouched, and you and the other friend jump ontop of them crouched and never move! if you move, or say a talk command, you fuck it up.
If you follow this method, this is the EXP - Rank range you will get.
SFC you will get 5-10% per game
MSG you will get 4-6% per game
CSM you will get 3-5% per game
2lt-1lt you will get 1-4% per game
CPT - Major you will get 500 EXP to 3% per game
This method is called the corner trick and has been confirmed working the best by me , and @Stephen .