Experience does help in sports betting, but luck matters too which is why no amount of research can ensure wins frankly speaking. Parlays are my favorite type of bets, but I rarely win them for obvious reasons.
My suggestion to punters is to not blindly tail op's tips and invest only what you're willing to lose.
Obviously, experience helps us a lot in sports betting. that's why every time we place a bet, we have to research it. involves insight, knowledge, then analyze it. but you are right, no amount of research or analysis can guarantee a sure win. because, if in a sports match it can be predicted with certainty, accurately and precisely. then sports betting, will not be interesting anymore.
However, that does not mean that what we research is useless and useless. because for me, that is a very important part. why, because we need all the information from the team that will compete, including all the latest information. therefore, that makes our judgment in every bet. because, we will not bet blindly without having the slightest knowledge about what we are betting on.
By the way, if you always lose on your parlay bets, maybe you should try another option. for example, only choosing three teams from the many teams that will fight. Also remember, engage analysis, then let luck decide.