...//:::
Seriously, this actually needs to be explained.
The issue begins with the fact that you have flaws with the semantics of the words, and that leads to the grammar itself.
Since, in our academic preparation we are taught language, spelling and grammar, and with that having a clear understanding of our language we can understand it.
This is an example that you can extend to many activities of daily life, which use similar nouns.
Now, I think that's where your confusion comes from, since nouns are accompanied by adjectives to give meaning to the sentence, so one of the reasons why you fall into that elementary school boy confusion is that you didn't go to school or it's a matter of your language or culture.
But in any case, the noun casino, or sport becomes an adjective (or vice versa) the moment you use it, depending on how you are expressing yourself.
So, in the jargon, or Anglo-Saxon grammar, this differentiation is important and binding to the action in relation to the differentiation of the fact in a casino or sports betting. Hence, its use for grammar or slang in the corresponding niche.
I sincerely think that you are not a native speaker of English or your culture uses another type of jargon, it could also be that you do not have the slightest idea of what a chance bet and a sports bet are in their mathematical principles.
In short, it makes more sense to have asked the difference between "bettor and gambler", since these in themselves define the previous point, in fact they are similar but very different in the individual as such.