How to force OS X to set the starting location of NSWindow

How do I force OS X to place NSWindows in a sane default tile-like location? For example, when I open TextEdit and create 10 documents, I can see that all the windows are the same size, but someone is smart enough to nest them a little. I'm pretty sure the app doesn't do this in code.

(I need a code based solution, not NIB / XIB).