[NTG-context] filling page to bottom

I find that the current (default) settings tend to break pages early, leaving a fairly large amount of whitespace at the bottom of the pages. Obviously in order to avoid breaking paragraphs or to avoid small parts of a paragraph at the top of the page. What parameters do I have to tweak to fill the pages more completely? Because I planned already to examine all pages individually for their appearance, inserting breaks by hand is not the problem here. dr. Hans van der Meer