dear will, it took long because only yesterday i needed to check on something and, by chance (if i may say), i came over this page - not because i've been thinking about the answer since september :))))
the shortcut is the following: select FROM a list / select FROM AMONG a larger number of things/persons etc.
you made quite a research on this matter, as i can see :) however, the cambridge definition at the end of your reply makes it clear for everyone, i think :)

as i see it, either you say "select a winner from the list of participants", or "select a winner from among the participants"