in the SHORT-TERM, how much can you weather bad cards in a single SNG?

i'm assuming cold cards pre-flop and/or poor flops for you (either you didn't hit or your high pocket pair is now precarious). pretty much nothing we can about being rivered (except having built up chips before that moment).

my thought is that in long-run, we want to crush SNG with good cards, have excellent chance to place top 2/3 with mediocre cards and have chance to try to squeak into 3rd place with poor cards. i suppose you'll bust out early up to about 20% of the time too..... do people think that's too optimistic??? or unrealistic???

just trying to reconcile my experience with that of others.