This killer whale gambler negotiates his own terms with the casinos so that he has a slight edge - and then he eats them alive. The big short of casino gambling.
Blackjack and craps according to most has the lowest house or casino advantage over the player. Roulette has a higher house or casino edge. As for roulette, I think the difference is the zero and double zero. I think the European casinos have just one of them which accounts for the 2.63% worst roulette comparing the US to European version of the roulette wheel.
You need to understand one thing about casinos is that they always win. So, don't try to beat them. They make a living of ripping people off. The other thing about stock market is that the gut feelings are strong while investing in them. So, invest in that business in which you are confident enough.
I could go on and on about this... I have been a gambler for decades... no YOU will NOT win over any considerable period of time.. PERIOD. No system will ever beat the house advantage,, ever... now as a side note... in California where I live you can "player bank" card games. In California card rooms the house cannot be the bank. Players can if they wish,,, so you can get the same advantage as the house by being the house.
You said that you have been playing for decades ... but as time goes on ... new opportunities and various conveniences appear even those https://www.profitsquad.co.uk/matched-betting/casino-calculator/#/ https://www.luckymobileslots.com/casino-bonus-calculator/ https://pennsylvania-online-gambling.com/tax-calculator stupid (sorry for my French) calculators, it's easier for beginners to get into the rhythm and it's easier to calculate their money
The reason speculation can work for the small trader is we have the significant advantages of not moving price with our orders, and the freedom to get out whenever we want. If you don't know the game, and don't know your advantage, how can you trade from a dominant position?
Back in the 1980's use to fly to Vegas every weekend and count cards in Blackjack, did well till they got up to 4 decks where my odds became 50/50. Decided to learn scalping/day trading, for several years would have done better at Vegas, LOL...Back in the day there wasn't any giant casinos except Mirage and volcano. Prices of meals, food, liquor and entertainment was cheap. Casinos would even pick up air fare or they saw you played big and look like you are losing, take couple chips and put in pocket every few hands.