I finished most of my marking for this term weeks ago, but a stack of late essays is still staring balefully at me, while insistent student emails keep peppering my inbox: when, they all want to know, will I mark the essays that came in after the end of the term? It is in this mood that I contemplate the marking recommendations provided by Concurring Opinions (via Organizations and Markets). While designed with exams in mind, I believe I can see some potential to modify this technique for essays…
Further nuances of this marking system, including the management of those difficult essays that span two steps, and the treatment of outlier essays that fall far from the main pack, are discussed in full detail in the Concurring Opinions article.
[Note: image @2006 Daniel J. Solove, Concurring Opinions.]
Rough Theory 
The simplest answer is to give them all A’s. Everybody wins!