Last year it was all about five at the back. Louis Van Gaal arrived at Old Trafford with a plan, three central defenders and two wing backs. For one reason or another, it's never seemed to work in the Premier League and once again it didn't.
Before long, the Dutchman ditched that plan and reverted to a good old flat back four. Some had suggested that he may revert to five at the back this season but it seems that is not going to be the case with Van Gaal taking the unusual step of revealing his first choice defensive line-up over a week before the start of the Premier League.
Against PSG last night, Van Gaal started with a back four of Darmian - Jones - Blind - Shaw and following the 2-0 defeat in Chicago he confirmed that he would head into the opening day of that season with a minimum of three of those players retaining their positions.
I have to start with the formation and when the formation is doing well, I let them play in that formation. I think I shall play Shaw with Darmian, and with Daley Blind. The right central position I have to consider.
Phil Jones is the only starter from last night who is not guaranteed to line line up against Spurs next weekend. Van Gaal confirmed that he had yet to decide which of Jones or Chris Smalling would line-up alongside Daley Blind at the centre of United's defence.
Given Daley Blind's versatilely, that is certainly an interesting indication of where Van Gaal sees the former Ajax man's primary position this coming year. It would also seem to suggest that Marcos Rojo is still very much in the dog house after being fined two weeks wages for failing to make it to the US with the rest of the squad as a result of passport issues.