design - What reason could Nintendo have had for putting the A and B buttons in a non-alphabetical order?

When Nintendo brought out it's first game system, the NES, it had a controller with four buttons:

• Select


• Start


• A


• B

However, somewhere, a designer, in their infinite wisdom, decided that the A and B buttons should not be in alphabetical order. So the B button was placed to the left of the A.

The reasons for this have long puzzled me. Surely the layout is counter-intuitive, and has confused many a gamer.

Can anyone suggest the reason for this design?

Answer

I'm guessing they viewed the button on the right hand side as the primary action button as it's closer to the users thumb, with the button on the left for secondary/less-used action, as it's slightly further away from the thumb (more of a physical exertion on the user).

They then may have wanted to label them accordingly - so A for primary button, B for secondary. Perhaps they felt it odd to name the primary button B and the secondary button A.

A-primary B-secondary

does appear more memorable. Maybe it does not matter so much for the physical act of playing but for things like explaining the game moves in instructions or for gamers discussing/explaining moves to friends etc. it probably makes it easier to communicate.