In my honest opinion, the common mistake might be you pressing your stake amount above the decided one, outside that I don't think mistake is what makes us lose in gambling. We lose because it normal and part for the game not because we make mistake, if we always assume it's because of our mistake then we aren't ready to accept our responsibility.
Once we have set of rules we must follow, abide by it regardless of any situation. From previous post made I observe we talk about negligence not mistakes.
I enjoyed the way you placed this comment. You know when we don't accept the facts that it's not everything that doesn't happen the way we wants it is mistakes. In gamble, losing is like a normal thing that happens, but it's only a gambler that thinks using spirituality will help them to achieve what they want from gamble are the people that won accept the facts that losing is normal. It's luck that allows us to win. Even if we add the whole spiritual things on our predictions we can't win if we aren't luck at that particular point in time.
