That's the thing. I'm not a narcissist, and my confidence in my approaches is driven by the objective statistics and uncertainties of the approach and NOT my ego.
If I think there's a 90% chance something will fail but there's a good reason to try it for the 10% scenario in which it succeeds, that's exactly my confidence and I'm not going to coat it in some bullshit pitch about how I'm confident it is going to work. If there's an 80% chance it is going to work, I will not lie about the 20%. And if I say 98%, it's actually pretty damn near that. The 2% accounts for my typical sick days per year.
Your job as a manager is to deal with these statistics and hedge the risks. Hedge funds do it with money, you do it with people and resources.
Unfortunately it's the people who say it's going to work 100% and actually fail 50% of the time that get the love of typical corporate managers.