Two of my favourite runs here are on Hakuba 47. They are marked as Double Black Diamond as on anything but a powder day they turn into a field of moguls the size of volkswagons and will challenge the best of skiers. On a deep powder day though they offer the pitch required to be able to get the speed you need. It can snow a meter overnight here and the simple rule of thumb is the deeper it is the steeper you need. Another tip is to don’t fall over on those days. You will understand why not when you do.