...all of them are the same . you can loose or win depending on how lucky you are
I don't agree! There are many sports bettors who profit year after year. They are not lucky, they are smart. They are good at evaluating sports events and good at money management. It is hard work.
Yes money management is also a key factor but that doesn't means you will not lose. It can result in either ways- Net Profit or Net Loss. Sportsbettors placing stakes on the basis of the confidence of their selection always end up making profits but luck factor also comes in between. Whatever they make over a year also contains some losing bets as well.
I am poor in ascertaining stakes and thus I always end up playing all-in when I get a bit careless in a try to overcome my loss.
Sure, money management is never enough on its own. The first and most important requirement is to be able to identify "value" bets - that is, bets where the price is higher than it should be. Without that we cannot hope to be profitable.