But they are invisible :)

As I understand, context lines is option to skip less lines then window height when scrolling.  However, it heavily affects how scrolling is done.  For example in non-0 context lines setup, when you scroll down (with M-v) from the very bottom of the buffer and only one line is display in the buffer at moment, scrolling won't even move a point!  just show more content.  At least now, I see this context lines concept very complex, undocumented, triggering unexpected results.

For me, scrolling is just a way to *move* your point fast in a predictable way, showing maximum content to the user, that is not what we get with default Emacs settings right now.

I would like to have scroll behaviour I got with setting context lines to 0, but yet skip less lines then window height :))