Exactly sharing your wins is base on ones choice , is not a much . Sometimes one can win certain amount of money and he or she would be overwhelmed with joy , and with that they can just easily share out some portions of those wins . Especially when the win is pretty huge .
There are some winnings that come with the joy of sharing; there are also some that come with the player just keeping everything to themselves because of how much they might have lost before that winning finally comes through for them, and that moment, even if you are aware that they just won a game, you might not get tips from them. There are some who will just willingly, with the joy of winning, share almost everything with others. It happens; it all is based on the mood the player is in and not entitlement like some close friends feel to the winning.
It all really depends on the wishes of the gamblers themselves, there are quite a few factors that encourage a gambler to share some of their winnings with others, whether it is because other people have been good to them before or because for example they are friends or give some of the winnings to others voluntarily without any previous story.
For me myself, I usually give some of the amount to people who are good to me whether in a gambling environment or not, such as my fellow gambler friends who always give some of their winnings when they win which I can use for gambling capital, but in the end it depends on the gambler themselves because they are free to make choices.