Well, I guess many of the sites can add fake information about players just to distract newcomers with misleading stats, etc. Also, in general, it's hard to get big profits with gambling afaik same as with casinos but some people have great luck and win big amounts of cash. Additionally, I suppose many gamblers who try to make their living by using it try to use maths, strategies and other stuff to make it more likely happen. Thus there's no exact answer to your question it all depends on a context.