Interesting points. I do suck at hiring but I also think I'm better than average at it. Its just a really hard problem where if you are really bad at it in some absolute sense you are actually pretty good at it in a relative sense. But yes if I was significantly worse than the average of my peers then my boss should fire me. I'm not trying to get all A players and I agree with your comments regarding that. I also edited my question as I see "very mediocre" isn't what I meant. Have you ever seen a below average developer turn into a better than average developer?