When it comes to sport betting doing a good research is very important, those that always study a game very well and conduct a good research about the game and the players always end up winning more than those that don't conduct research, a friend of mine said he usually do not conduct research before playing a game because it never works for him, conducting a research don't mean you will always win the game you predicted but you have a higher chance of winning when you research.
Doing research will help you analyze historical data reveals pattern that can guide your predictions, there are history that will help you make good prediction, Research helps you rely on facts rather than emotions.
Betting without research means you are gambling blindly.
Doing a good research can increase the odds of winning, but it seems your friend thinks that it should guarantee a win, something that is impossible as anything can happen during a match and an underdog can always obtain a win through a weird series of circumstances happening during that specific match, and if he does not understands this then I do not understand why he makes sport bets, as analyzing the matches is almost the whole point and the most enjoyable aspect of sport bets.