[sopchi]

I don't quite believe the dice roll metaphor tells the whole story. It is not all or nothing, it is not how it is done. On that subject, I recommend reading the book by Ed Viesturs [1], first American to ascend all 14 highest mountains (summits > 8000m) without oxygen. His take is: to do all 14, you need to come back alive every time. So knowing when to give up on an attempt and turn back is key. Above 8000m (reasoning impaired by lack of oxygen), when the weather is still good, when you are so close to the top, and knowing you will have to wait years perhaps for the next opportunity it can be really hard to make that decision correctly. And picking a partner with not just all the skills bit also the same risk tolerance is vital.

[1]: No Shortcuts to the Top: Climbing the World's 14 Highest Peaks (October 2006)