We changed quite a few years ago how our bigs/littles are assigned (just in time for me to pledge). Neither the active nor the pledge has any say - littles are assigned to first anyone who has not yet had a little (we average a pledge class of about 3 or 4, so this is quite common) and then by who is the most senior. So if you had say 3 pledges, a sophomore and two freshman, and 2 seniors and two juniors who'd never had littles, the sophomore would have a senior as a big, 1 freshman would have a senior class big, and the other frosh would have a junior class big.


Unfortunately, at least in my case, it never really worked out - I never became very close with either my big or my little because we were just too different personality-wise (although the two of them would have gotten along well had they ever met!)