Good judgment manages uncertainty; it does not abolish it.

Good thinking does not remove uncertainty; it changes your relationship to it. You can improve your odds, limit your exposure, keep options open, and stay solvent enough to try again, but you cannot arrive at a place where the future is settled. Any method promising that is selling comfort, not judgment.

Instead of asking how to be sure, ask how to be wrong safely. What is the size of the bet, what happens if it fails, and can you still be standing afterward. That question is usually more useful than more analysis.