The similarities and differences of arrangement and order of episodes in the gospels of Mark, Matthew and Luke have always been one of the major criteria for resolving the Synoptic Problem. How important and how reliable are arguments based on such considerations, and where might they lead? Here, Neville reviews these issues in detail, explaining the significance of his conclusions for understanding the literary relationships among the three Synoptic gospels, and particularly for the competing theories of Markan priority (the standard two-source hypothesis) and Markan posteriority (the Griesbach hypothesis).