Unlike most single-game wagers, futures bets are made on possible outcomes that are often months into the future. For example, you can bet on who you think will win next year's national championship in college football.
All futures bets need to have a higher +EV than single-game bets? Why is this the case? Because futures wagers require you to tie your money for several months so you must factor in the opportunity cost of not having access to that money.