I'm an atheist and when I started to play, I had a fun experience despite of what I won or lose because I bet small amounts. Then I got addicted because of some big wins so I started to gamble much.
Even if I wanted to think that maybe my winning and losing isn't getting impacted by anything external, I believed otherwise. I believed my winning is the result of the color of the shirt and wearing, music I'm listening to, time of the day etc. Then when I lost big, I prayed to God to help me win/recover. I saw gambling as life and winning is heaven and losing is punishment from God.
Then slowly I stopped and the addiction got away a bit.
What's your opinion, do you believe in God/power that you think may help you win? I think gambling has the potential to turn an atheist into theist because of fear/risk it has.
Since gambling is luck based, You can only pray to God that you win the games. If you pray and then you win, your trust in God will be built more and you will pray every time before you play gamble.
If you are superstitious and think a certain color or thing can help you win, then you are totally wrong. You should not relate your winnings/losing with such things.