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.
The downside of that feeling is that you might become over confident to use a big amount in the game since you're to a large extent certain that you're going to win.
Can we still say we are gambling if the event is something we are at least 90% sure that we are going to win?
I think nobody would place their bet if they were uncertain. They choose that team because they are certain and feel they will win. Placing a huge bet could be something too risky. However, what if it wins? For sure, you will regret it if you only place a small bet because you're thinking negatively despite the feeling that they will win the game.
In gambling, trust is the only thing we hold when placing our bet. Trusting the team matters. If we feel uncertain, then we don't have to bet as well. It is as simple as that.