Hello Pete,
thank you for your response.
Many people play ranking games and a lot of them play 20 games and more / week.
So 10, i think, is a value which has to be played, to keep a ladder alive. Everybody may decide, if he has enough time to play ladder. That is the basic decision everybody has to make.
Otherwise you have these guys like Checkraiser, playing 20 games, be No. 1 and then go offline... Next autumn No.1 again... (btw, this guy is me

)
I think it will always be hard to find a balance between hardcore gamers and those which play from time to time. But one thing is clear: a ladder loves activity.
And become No. 1 should be hard. Stay as No.1 should be harder.
As long as we don“t have a good working skill based algorythm, we need to work with the one we have.
What the others think about 10 games / week?
Too much, not too much, or a good number?