Some people love and knows everything about soccer why some people love and knows everything about basketball, so also table tennis, volleyball, baseball, horse racing, handball, snooker, boxing, cricket, golf etc. Any sport you know very well, you can gamble on those sport and avoid gambling on sports you know nothing about, one of the reasons why some set of people lose money a lot when it comes to gambling is because they gamble on sports they know nothing about with the slogan " gambling is all about luck" yes gambling involves luck but that those not mean skill and knowledge is not involve, if you gamble on sports you know nothing about then you are gambling blinding and your chance of winning are very small compared to when you know everything about that particular sport, when you know a lot about a particular sport prediction will be easy for you.
Is true that knowing everything about a particular sport those not grantee you winning always but is an added advantage when you are gambling because it brings you more wins.
Sports games which you mentioned if one has good knowledge about these games then he can earn good family money through gambling because sports can always be predicted well if you have good knowledge about that sport.
But a big problem is that most of the gamblers who play gambling do not have good knowledge about gambling games, they jump into gambling only because of the greed of money and seeing the success of others and continue to bet with huge expectations and they end up losing a lot.