As an autograph collector, I often wonder how the experts at PSA, JSA, etc. authenticate autographs of people that almost never sign anything. Therefore, there are very few or sometimes, just one exemplar to go by and it may not be known when it was signed. For example, Steve Jobs, Stephen Hawking, or "Sholess" Joe Jackson. I'm sure there are many other.
So what's an expert to do when he's asked to do so: authenticate them or decline? Any thoughts?