It will never be exact but the wins and losses will be close to the math. Still, as time passes inexorably forward and a roulette player plays more and more decisions, the roulette odds begin to take shape in the real world. You may find yourself wallowing in a massive losing streak or cheering like a wild man and strutting through the casino like a god who has brought down Lady Luck with a wild streak of wins. In the short run the game of roulette (or any casino game) can be totally crazy as in you may hit many winners or you may hit few or no winners in dozens upon dozens of decisions.
The roulette odds are just that, odds, a long-range figure based on math. Let me take a simple example first: What is the basic house edge at roulette (yes, both the American double-zero wheel version and the European single-zero wheel version) and how does that basic edge translate into roulette odds? They have no idea what those roulette table odds actually are or how they relate to roulette’s probabilities. That mindset concerns the fact that many casino players will play games not possessing any idea of what those games’ house edges are or, if they do know the edges, they have no idea what those edges mean in terms of money (won or lost). I am fascinated by a certain mindset that exists in many casino gamblers.