When you say that you pray to god that you win in gambling makes me wonder which religion do you belong ? Most religions prohibits gambling's so how can you ask God for a win which is totally not allowed in the first place.
For my experience, no one pray to win in gambling, people just randomly win or lose based upon their luck factor.
You did not read my post post correctly, let me quote the most important part below and you can read, I hope you will not get me wrong next time. Why would someone pray because of gambling, that is completely not making any sense. Gambling should just be taken for the fun of it, even if I lose, how much do I lose, just a little amount of money that can not affect me in any way. I am not new to gambling at all, I know how things operate while talking about gambling.
This thread is already long but I have not replied here before and I think my reply is just a life experience about what I have noticed about prayer and gambling. I noticed if I move closer to God, I win more than when I do not, if I pray more, I win also, but I always think this is just normal thing and luck, I do not pray because I want to gamble because if I lose, there could be a thinking that God make me lose it when God is not the one that says I should gamble, I just gamble without praying because I am not that type. People praying before gambling to me is not what that will determine their winning or losses, what will happen will happen, what they need most is the knowledge and experience about how to win, taking gambling not as business and also not as profession but just as fun and entertainment because gambling is not what worth praying about.