How can you aculate the most points in Black Ops Nazi Zombies?

well i shoot 5 times then knife in 1st round, then when its round 4 or 5 (and still havent found box) ill buy the mp40 upstairs. i wouldnt buy the bowie knife just because its useless after 10.and ive heard that if you let them through the first couple rounds u can get power ups faster!