That is the way I think of it, and that was the assumption I have been going on through all my time in this business. "Blowing out" an account means it going from whatever was in it, to zero. Losing 20% of an account is just a large loss. Have I been thinking in wrong terms?
Most certainly not. Down 10% is taking it on the chin. Down 20% is taking it a bit lower. But you examine methods, stops, and expectancy; pull up the boot straps, and trundle on, grateful that you have 80%-90% of your shit together. "Blowing out" is end-of-game stuff.