very rarely against the majority because the risk is very large, in certain matches for example many people who like a team that is known to always be able to win a match or it can be said that the team has never been defeated, but when meeting an ordinary team of course most people will be more choose the most favored team.
But all games have a upside down,specially in team sports when the function of each others is very important and sometimes its go the other way in which brings the majority lose
But you are right mostly the more believers is the one who always win,maybe it attracts positive and luck for the said team or player?