Maybe just take the next block ID and use the last number, if higher or lower than X the tie goes to one or the other. Same can be done for 3 and 4 way ties breaking up the numbers to 3 and 4 divisions.
That's similar to the mod suggestion. As you described it only works when on item needs to be chosen (A method that generates a permutation could be used for, say, choosing 2 items out of a tie of 4). Anyway, my main point is that I don't want to describe in our bylaws "We will take the block hash and do modular division and X Y Z...", I want to be able to write "We will use the standard blockchain tiebreaking protocol".Ahh, this is the first I have read of someone wanting to use the blockchain for tie breaking. A few methods for voting but not tie breaking.
Perhaps you could come up with the standard
