You know one very mistake some people do is to have a high hope or rely on what they believe can be possible outcome in a football game and end up gambling more than what they can afford to lose, honestly nothing is guarantee and the whole system is unpredictable. Indeed, it was a surprise winning three zero without a returning goal is something that no one could have imagined in that match, even those that predicted both teams to score will still be at lost, we can't get of seeing surprises hahahah but we will rather get used to it in especially in terms of overly hope for a favorite team to win a match.
No matter how strong or a weak team is, there is always a possibility of an upset. Taking this into account, we should not bet more than we can afford to lose or at least have a plan as to how much money should we bet in each match. Also i think that in an upset, the gamblers loses most money but at the same time the gambling site makes most money, as the gamblers losing money is actually the casino gaining money.
I do not know whether to call Bayern Munich unlucky or they played badly, as they had 80% of the possession in this match but still they can't make a single goal but instead they conceded three goals, unbelievable !!!