The gray ones are unrated games. All the games that make it to the Seek Graph make it because they are custom or unrated. Few people want to play them.
Most players pick a time control and set a rating range (above and below their own rating) and just let the system match them. It is much quicker.
I think I have a problem when I search for an Open Challenge with the Graphic. There are Tournaments with no info and open challenges with Players name,nation and connection level, but NOT Rating points..
Why Rating points are disappeared? Also in the Live Chess menu Settings button disappeared too.
IS this a bug or something?
I post 2 screenshot to be more specific.