I am used to thinking three or four months in advance, about what I must do, and I calculate on the worst. If I take so many precautions, it is because it is my custom to leave nothing to chance. – Napoleon I, in a conversation with Marshall Muart, March 14, 1808.
If you want to increase the probability of project success in the presence of uncertainty, it would be good to take Napoleon's advice and calculate on the worst a few months in the future. By calculate it means making estimates since all outcomes in the future are probabilistic.