If you had a choice between and odd-on sports bet, between two teams, or an odds-on favourite in an 8 horse field of gallopers, which would be the better or safer Bet? The one with the highest predictability of an outcome, despite what the price says?

In the horse race the favourite's got to get in front of 7 other horses in running. In the horse race the favourites probably carrying more dead weight, as it's a handicap. The horse favourite is competing against 7 other 'teams' as it were. There's probably a good argument for Backing the horse too, or is there?