I only experience this when I was in my teenage days, back then the local internet cafe that I used to play or hang out was the main shop that the locals would go to play and have some bets on their games.
Back then I know the players who would have a match so I know how good they were compared to their enemy team so I am sure that they would win, so I borrowed a small amount of money from my friends and bet on that team to earn and the result was actually how I expect it to be.
But other than that I haven't tried to do it again, I would only borrow to invest or gamble if I am sure of that I would succeed.