Good question. Some of it is quibbling on words. My general take on people's ability is it's a fat tailed distribution on both sides. There's a middle that i

Good question. Some of it is quibbling on words. My general take on people's ability is it's a fat tailed distribution on both sides. There's a middle that is fairly tight in ability, and they perform good or bad largely dependent on the circumstances system (including management) that they're put in. The upside and downside surprises can go very far on both sides of the mean. Which means slightly bad hires tend to be products of a bad system, which is what should be fixed. But very bad hires can do an inordinate amount of damage even relative to their small probability. P(x) * Value(x) comes out to a very large negative #. (Similarly P(x) * Value(x) comes out to a very high absolute # for the great hires) Now what's the probability of a truly awful hire? Depends on how well you hire. I suspect it's somewhere between 1% and 10% based on the organization. Same on the upside.