I just re-read the entire 'Storm and Silence' series this weekend, and the new assassin there, Kael, really got me thinking. He never wins a straight-up fight, not if he can help it. It’s all in the prep work. He spends three chapters casing the embassy, learning the guard rotations, the delivery schedules, even what brand of soap the head of security uses to figure out his allergies.
His greatest trick is making the rival think they've won. He'll let a surveillance team spot a decoy, let them intercept a fake plan, and then strike while they're celebrating. It's chess, not checkers. The real victory happens before the knife is ever drawn, in the quiet moments everyone else overlooks. That meticulous patience is what separates the fine from the merely good.