You go with what works for you; those who watch almost every match in each season, some of them don't waste time in running research about previous matches again as they watch both team performance before either last season or just in a concluded match; they can make their prediction from there.
Some people are just like your friend; even after spending hours and days making your research on your game option, sometimes your prediction comes out wrong, while the next player who just spent a few minutes selecting random matches ends up winning. It's just all about luck sometimes, but the research just helps increase your chance of winning.
I agree,you go with what works for you right.Sometimes even this researches don't really fix or give that which is expected,you'll just try to familiarize with the game rules,odds,and game structures.
Mostly,almost everyone that uses this medium to gamble has attested to the fact that this feature is vast in transparency and creating a longer lasting experience and minimize the risks of losses.