[ilya]

Are you sure this isn't a purely theoretical question? I mean, how often are you down to 4 with the blinds still at 50/100? I play about 20 $10-$20 SnGs a day on average and I see this happen maybe once every two or three days.

With that caveat...I don't think it matters how many BBs the 4 stacks have "on average." What matters to me is my stack size, the stack sizes of the small and big blinds, how soon the blinds are going up, whether the small/big blinds are passive or agressive & loose or tight, how likely they are to pay me off postflop, and similar considerations.

P.S. I just realized you may be playing on Stars, where all manner of wondrous things are said to be possible. In that case, disregard my first paragraph. When it comes to Stars SnGs, I *really* don't know what I'm talking about.