Shivalry

Some proof that Leigh's predelicition for shivving pays off:

"...let them approach your window and yank off some boards, and then finish them off with your knife before they can enter the Spawn Room. You have now gained 10 points for each shot on their body, 130 for finishing them with a melee attack, and 10 for each board you repair."

Original article here.

Another tactic to consider:


Rounds 1-4:
Just knife the zombies. It saves you points and isn't exactly difficult. Open the stairs on round 4.

Rounds 5-7:
Everyone should hit the random box as much as they can or until they get good guns. At about round 7, head to the doctors quarters but dont open it. Turn the zipline on (but dont use it yet).

Rounds 8-12:
Stay in the entrance to the doctors quarters. Around round 12 everyone should have plenty of points. Open the doctors quarters and grab whatever perk you can. Then use the zipline to take you up to the main balcony. Have someone covering each window and someone covering the stairs. Also open all the doors when you get the chance.

Rounds 12 onwards:
Now just stay like this, perhaps switching around when ammo becomes an issue. When you need more guns/ammo/perks, just leave a crawler and go to the box (wherever it is).
When you have a dog round, everyone should cover the balcony in bouncing betties and get onto the zipline (but dont use it.) Then just gun the dogs down. When you finally get overwhelmed, just take the zipline down to the doctors quarters and make your last stand in the back room there. Voila!

Voila indeed. Cheese eating surrender monkey.