likelihood of getting a bid

Not true. Just keep an open mind and maximize your options and its very rare to not get a bid. The girls who dont get bids are the ones that think they are too good for some chapters and quit themselves. Jokes on them though because no matter what being in a sorority is better than being a GDI.

The truth is there's 1600+ women going through recruitment this year and a max capacity of 900 bids. Women drop recruitment for all sorts of reasons however and that factors into that stat.

Lots of girls don't get bids because they drop out of rush entirely. whether they dont get asked back by their favorite house (which, unless that happens really late in the rush process its usually the "top" houses), they rushed for the heck of it and didn't like it, or they drop for financial reasons. If you maximize your options (ie, list both houses you pref with) pretty much every girl who goes through all of recruitment gets a bid.

The '50% don't get a bid' this is true but with one HUGE caveat, about 80% of the girls that don't get a bid are girls that drop recruitment of their own accord. A majority of the other 20-ish% of girls are dropped after the first day for grade related reasons. There are always a few girls who are dropped throughout or will not get a bid at the end but the number is very small.