This will sound very stupid. I switched to a Mac about three years ago, but have never quite figured out the manner in which windows are positioned & sized in OS X. I generally like my app windows fill the screen and achieve this by manually dragging the bottom right corner of a window. But when I launch a new window in the same app, it never has quite the same dimensions or positioning as the already-open window. Surely there must be a preference setting somewhere to make this so? And I can't really understand the behaviour of the "+" button. Logic would seem to dictate that clicking it would maximize the window. But the windows seem to resize to arbitrary dimensions. I'd be grateful if someone could shed light on this niggling issue!