Anecdotally my experience is that for every one really good developer there's about 25 or 30 mediocre ones, and 5 or so really terrible ones. This is based most

Anecdotally my experience is that for every one really good developer there's about 25 or 30 mediocre ones, and 5 or so really terrible ones. This is based mostly around what I've seen conducting interviews in my area. That is also highly variable, I did some interviews for another office (in another country) and saw ratios more like for every three good developers there were two mediocre ones, and no terrible ones. Maybe we just had a much better recruiter feeding us candidates in the other country, or maybe they just have exceptional programmers living there.