The cards/odds are stacked in favour of somebody/something - Idioms by The Free Dictionary
the cards/odds are stacked in favour of somebody/something
the cards are stacked in favor (someone or something)
Someone or something is very likely to be successful due to some existing circumstances, conditions, or obstacles that will aid or benefit someone or something. The cards were stacked in favor of the film—an all-star cast, a huge budget, and a great marketing campaign—but it turned out to be one of the biggest flops in the history of the industry. Everyone knows the cards are stacked in favor of those who already have business connections through their friends or family.
the cards/odds are stacked in ˈfavour of somebody/something (British English) (American English the cards/odds are stacked in ˈfavor of somebody/something) it is likely that somebody/something will succeed because the conditions are good or because somebody/something has an advantage: The odds are heavily stacked in favour of Manchester United, who are having a very successful season and who will be playing in front of the home crowd.