reich runner

okay this strategy is for serious players. you need some serious skill. the name for it is something really fancy, but i call it "Reich runners"
to sum it up, knife your way through levels 1-3, pistol your way through 4-5, and carbine it up a little untill you enter round 10. once you get to round ten, (you better be pretty good) open the help door. this should be between rounds, when theres no zombies. use the random box untill you get an automatic, good clipped weapon. (Keep buying weapons) make sure your variety is both automatic, and has a very large clip. the zombies will be running very fast, now. just wait untill they start pouring in through all directions, and just run around the help room in big circles, turning around to unload on the large pack of crazy zombies. this should work great if you keep running, looking forward and sprinting when your reloading. do this untill round 35. then open the upstairs, open the other stairs, and start using the entire house to run in big circles. (*starting room, help room, upstairs. you should make round 60. my current record is 75 using this strategy.