Although the boss has always made subtle tweaks to his teams, he has generally sent the players out in either a 4-4-2 or 4-5-1 formation.
Certainly, width has always been present and central to United's attacking philosophy. In recent weeks, however, Sir Alex has experimented with a narrower diamond formation that eschews the traditional wingers in lieu of more bodies in the middle.
It's proved successful – United beat both CFR Cluj and Newcastle using the diamond – and the manager believes it now forms a crucial part of the Reds' armoury.
"The diamond is seen as a little revolutionary because it goes against our history," he conceded. "But the level of the game in England and Europe is so high now that making yourself unpredictable is a strength.
"Teams will now have to think about whether we will play with two wide players or in the diamond because we have the players who are capable of doing both things.
"Players like Shinji Kagawa and Tom Cleverley can play very well in the diamond, while in Antonio Valencia, Nani and Ashley Young I also have very good wide players."
Abandoning width completely would never be popular with United fans – some of the club's most celebrated figures have been wingers – but evolution is key in the modern game and Sir Alex must employ the formation that gets the best out of his personnel.
"The initial reason for signing Shinji Kagawa was his ability to play behind the strikers," Sir Alex