At first glance, and following the elementary logic, betting on an outsider is just stupidity and madness. But this is only at first glance. If it were so, then no one would ever put their bets on such teams. But many players do have reason to make such bets. This may be, as you noted, the athletes you know are on the outsider team. And then you will not be ashamed to tell him that you believed in their victory and even put money on the victory of their team. This will definitely be a good incentive for your friend athlete. And he will certainly inform other players about it. And the mental attitude of any sports team, even an outsider, is important. So for some players, betting on an outsider team is the right thing to do, and from their point of view, this is exactly what should be done.
I don’t even remember the rare cases when outsiders win, which actually happens sometimes too. Then such bets will generally bring not a small profit. And at the same time, double joy for an accidental, so to speak, victory of your favorite team, and for winning money.
Well, maybe that's what will happen. But those who still bet on their team won't think like that, especially for people who are fanatical about their team. They might even bet for an amount that exceeds everyone else's. But for people who could see through the situation, they would probably act differently from other people so that each person would have their own choice. And it's up to them; we should also stick to our choices and not harm us. And if we think that betting for outsiders is best for us, we can just as well bet for them. So it will come back to each person's thinking.
Without proper checking it can lower down the odds to win since you don't know if the underdog team is complete. There are times that they are more behind since there main star is out of the game due to injury so to avoid this mistake and still want to make sure that you are in good position while betting on underdog teams a good research is really needed to know the current situations on both teams. Although its not wise decision to place bet on underdog team but sometimes its rewarding.
Sometimes, a match can change midway and it will surprise many people because they have chosen their team and now they have to see their team suffer a setback and look even weaker. This happens a lot in matches, so we have to do proper checks, as you said. And don't follow other people's opinions in choosing the team you want because you are responsible for your money and not someone else's. The important thing is that we have to be wise in betting and know when we are betting and when we only need to watch the game.