Bookies are middlemen. They do not attempt to predict the outcome of events (at least not directly) they try to wager an equal amount on all possible outcomes, and profit off the “vig”. Odds are set to have an equal amount wagered on both sides of any contest. (Same deal with point spread. The spread is where bookies think an equal amount will be bet on either team.)
I think that is what I was trying to say.
Odds are set to make sure bets on both sides are covered. Bookies don’t want risk having to pay their own money out.