# What is God's Number for the Rubik's Picture Cube?

It's been well known for a few years now that every Rubik's Cube scramble can be solved in 20 moves.

However, this is only for the case where the orientation of the centers is not taken into consideration. I couldn't find a reference for the picture cube, where face orientation does matter. Does anybody know a resource on the minimum number of moves required to solve a picture cube?

• Not a complete answer, but even on a standard rubiks cube, the sides and corners must be in exactly the correct position and orientation. The only difference is that each of the centers may be rotated to one of four orientations. Hopefully that is a start for those who write an answer. Commented Jan 24, 2015 at 5:59
• I think a counting argument gives a lower bound of 22. For a trivial upper bound, is there a short sequence to rotate a single center cube or multiple of them?
– xnor
Commented Jan 24, 2015 at 9:45
• @xnor: Could you expand on your counting argument? It's not obvious to me. Commented Jan 24, 2015 at 13:55
• @xnor Counting only gives you 21. Commented Jan 24, 2015 at 22:00
• By "minimum," do you mean "maximum" or "least upper bound"? The minimum number of moves required to solve a cube is $0$, which occurs when every piece is already in the correct position. Commented Jan 26, 2015 at 19:34