Ghost rating versus games played:
http://www.google.com/fusiontables/embedviz?viz=GVIZ&t=SCATTER&width=1200&height=640&q=select+col2%2C+col1+from+816576++order+by+col1+desc+skip+0+limit+500
(this graph has no caption :( however, to be clear, the highest ghost-rating (madmarx) is just shy of 800, and he has played less than 200 games. )
This following is the same chart, but zoom'd in on the 'normal' people:
http://www.google.com/fusiontables/embedviz?viz=GVIZ&t=SCATTER&width=1200&height=640&q=select+col2%2C+col1+from+816576+where+col2+%3C%3

+%27300%27+and+col1+%3C%3

+%27200%27+order+by+col1+desc+skip+0+limit+500
*here 'normal' is defined as less than 200 games played and a GR of less than 200.