There are event you can predict on that even though it's not 💯 guaranteed that you're going to win, a level of certainty makes you think that you're surely going to win.
Like PSG vs Chelsea and then they went ahead losing to Chelsea

, there's no guarantee about a future event , it's just what you believe would happen, doesn't mean another person won't see it differently no matter the level of certainty or whatever you think and lo you could be wrong as well .. that's why it's called gambling
Oh yes gambling is absolutely a game of uncertainty to which we shouldn't act with much assurance on any game between two teams wether its between two teams which one is weak and the other stronger. Chelsea Vs PSG match final was one game which left many gamblers losing so much of their bet because hardly did anyone thought Chelsea could have won PSG after watching how PSG won all big sides in all competitions.