Favorite/underdog: which to bet on?

Like in any sporting competition, we all have a favorite and an underdog. The favorite is the one who is judged the most likely to win, while the underdog is the one who is considered the least likely to win. To identify the outsider or favorite, it is only a question of the bidder analyzing the odds, the favorite seeing his odds collapse. Race horses have the particularity of having constantly fluctuating odds. The player often designates his favorite according to the extraordinary abilities of the horse or the recognized talents of the jockey. But the odds have to be studied until the last minute because the odds change according to the bets. The more bidders designate the same favorite as you, the lower your winnings will be. So is it better to bet on the favorite or the underdog?