In my case if ever I am not really familiar with a match I am not going to bet even a few coins but of course there's an exceptional depend on how hype the game is. In the same case like having an interest to bet in an unfamiliar match I would always go choose to bet on the crowd favorite but I'd still going to make my own research about the game so it would depend on what the players recent records, skills, potential and capability too
Sometimes you get lucky as the odds maker gives you a champion as an underdog because of the opponents hype.
if you are a familiar with the sports, it is not hard to bet on underdog if you know their capability to get an upset of the game. just like in boxing, the recent upset that i placed bet was on sultan vs caraballo match, i didnt put much on sultan but i have the feeling that he can possibly pull off an upset, because he is a filipino boxer, and we know, a lot of filipino boxers are dominating inside the ring, even if they have decorated opponents.
so what am saying here is that this depends on the situation and sports, if you are familiar and know the players, you will be more comfortable placing bets on underdog.