Same here... and I suspect the answer will be that it only works if it's lazy enough to survive past a fortnight. Years back I kept a scrappy notebook of daily ranges next to the implied figure, and it lasted about three weeks before I couldnt be bothered, mind you the little I did log made me size stops wider for a while.
If Shadow Trader has it down to one number and a glance, fair play to him.
G.
Yeah, from my point of view market allways change and you have to be able too.