And: Luck (because shit happens). I don't mean for this to in any way diminish his amazing accomplishments, but no matter how well he trains and how disciplined he is, he is always one unexpected external event (failing hold, rock falling from above, just enough loose dirt) from complete failure.
Alex only does dangerous free solos on rare occasions. He's certainly vastly more likely to die on one than the average person on the average day, but the fact that he only does it rarely is how he's still alive at all.
Nobody really knows exactly what type of risk he's taking, but my rough guess is that he's probably on the order of ~10x an average mortality rate (which is 1.5% / yr among males his age).
Whether that's insane or not is up to an individual. For me, it's a rare combination of crazy and rational, which I find fascinating.
