Make Folder, Subdomain Name, and Page Names Match Content
Humans categorize Joe Smith very differently based on folder path. So do search engines.
Create "Semantic" URLs that convey information:
Assume Bots Read All Your Code:
For the two pages above, you might use a graphic with "Karl Kelman" at the top of the page. If the page is about Karl Kelman and skiing, a good path for the graphic element might be:
And use an Alt Tag for the graphic element: "Karl Kelman"
Don't try to spam the bots with alt tag... ...that's something search engine technology can detect occasionally now, and they'll get better and better at it.