One of the things I have to do is mark test papers that come in at random over the course of time. Some I mark sooner rather than later. Why, because I pick the ones I find easiest to mark first and not the ones that come in first necessarily. But what's easier for me isn't for someone else and vice versa. It is a form of luck of the draw. So I can completely see how it works in the ECO office. Plus a bit of addedetc