what i like to do with my friends on a 4player game is once everyone gets enough points but the door closest to the gewher and then a few ppl buy the trench in that room. then get 1000 pts and but the upstairs debri. jump down by the bridge and go up against the wall and defend everything there while occasionally getting a new weapon out of box. When dogs come use the trench gun and when the box goes somewhere else buy the power and get juggernaut. also get the door behind the power and bowie knife.

Then have 1 guys gaurd window, 2 gaurd stairs, and one crouch at the hole in the wall on top of the stairs and shoot em down. when u get enough points go link teleporters and get perks, better weps, and upgrades out of pack a punch. so far my friends and i got to lvl 16 which i don't think is that bad. we always die by overcrowded zombies at the stairs so focus ur attention there. if u thought this was a good strategy reply and if u have another even better strategy reply too.

thanks, and hope i helped