Playing Poker with Cards

Hello, I am a baal teshuva (a person who has returned to observant Judaism) and I wanted to ask if it is permitted to play poker (card game) for money. It is important to note that I have a steady job and this is merely a hobby that we play once every week or two for amounts between 200-500 NIS per game (this is the amount a person could lose in an evening). Typically, one week I win and the next week a friend wins, and so on. I understand that according to the Shulchan Aruch (Code of Jewish Law), this is problematic due to concerns of theft according to rabbinic law, but we have found a solution: before the game, we transfer the money to one of the guys and also sign a document beforehand stating that we waive the money and transfer it to him. Thus, according to the Shulchan Aruch, we are not violating rabbinic theft. However, there is another issue where a player can sometimes lose multiple times, and that could be frustrating. Still, we all take this into account beforehand, and it is essentially a way for us to unwind. Anyway, I wanted to hear the Rabbi’s opinion on whether we can play as we do.