For me, positive mindset only help you make positive things, but it can't help you win.

As somebody that believes that gambling is a game of luck, I don't think that positive mindset will help you win although I'm not saying that as a gambler, you don't need a positive mindset because I always say that having a good or in this case, positive mindset can help you in different ways. This is very hard thing to do though especially if you're the type of gambler who's desperate in making money in gambling. Your desperation can lead you to do negative things.

Having a positive mindset matters when it comes to gambling, but for me, thinking on gambling as a form of entertainment ONLY and not a way for you to make money also helps as well.