Could it be that the rich understand financial management more?
I agree with you that the rich don't worry much when it comes to gambling. If they lose money, their life will be destroyed, their family will not be able to spend, they will not be able to buy food to support their family, and they will not be able to send their children to school, the rich do not think that. Due to this they have no recoil and feel comfortable playing the game. When they play with joy, without tension they win.
On the other hand, a poor man always worries about his money. If he loses this money, then his family will be in need today. He may not be able to make his child study well, not be able to manage the family well, and not be able to buy his mother's medicine. Thinking about all these things he makes mistakes and he loses.
So you say that rich people isnt able to place everything they have got? We recently got here topic where casino allowed drunk businessmen to place bets and in the end he has lost +100 million worth company that he was building all his life. Or you think that rich people are so reckless due to their wealth, that they can bust money without care? They would be poor, if they had such attitude.
Rich and poor does not win or lose more than others. They all gamble as much as they can afford and each with individual tactics and success.