Last year, 27% were eliminated in week 1, mostly because almost 20% picked Chicago to beat Buffalo. Two years ago, 22% were eliminated in week 1, more than half of them picked Tampa to beat the Jets in NY.
Just FYI, I have a church gig (I'm a musician). I'm usually home by noon, but sometimes I'm not. So if you make a pick (or change one), it might not appear in the spreadsheet immediately, but as long as the BBS time stamp is before the posted game time, I'll get you in.