One could put this down to changes in personal but for more than one player to make the same mistake over and over again, you have to wonder if they even bother looking into fixing the increasing number of things currently going wrong. Of course, once you establish defensive stability with a settled back four, it might be difficult for new players to come in and maintain that. Although, this is an argument that is countered by the fact Everton have, in recent weeks, been forced to field John Stones at the heart of their defence. Against Arsenal, the 19 year old with less than 20 Premier League appearances to his name looked far more assured and far more comfortable than any one of our own back four on the day. Stones has manfully stepped in for the injured Phil Jagielka in a way Thomas Vermaelen cannot seem to be able to do for Laurent Koscielny.