It is difficult to back many sailboats straight. Once all that rode is dumped out, how can one be sure that one is backing out the rode in a straight line.
I like to drop my anchor and ease out the scope as the anchor gently digs itself in. I give some easy tugs in reverse at 3:1 and 4:1 before I give the final test. Has worked so far and have not dragged yet using this technique. But then again, you know what the farmer said when his horse died: "Funny, he never did that before"