If I had to pick the single most important thing in trading, it would be risk management.
I mostly focus on day trading.
I usually set my risk-to-reward ratio at around 1:1 or 1:2, and when I identify a setup where I believe my win rate is above 50%, I repeat the same process consistently.
Risk-to-reward simply means how much you're willing to lose compared to how much you're aiming to make.
Even with just a 51% win rate and a 1:1 risk-to-reward ratio, you can have a positive expectancy over a large enough number of trades.
Trading isn't about relying on luck.
It's about building an edge, managing risk, and repeating that edge enough times to minimize the impact of luck.
More trades with a proven edge = less luck, more skill.