That doesn’t make any sense.

If you had a position that could be solved in 22 moves, you would start with making a move. This new position call it 21 would be different than position 22. Then you would make 21 more moves to solve the cube.

So, yes, it is possible.

I think what they mean is there are some positions that can’t be solved in 21 moves, for sure.

Just like there are some positions that can’t be solved in 26 moves, for sure.

Whereas the above number crunching proves ALL positions can be solved in 25 moves or less.

]]>“I’m guessing “there are no configurations that can be solved in 21 moves” means There are no configurations that are solved in a minimum of 21 moves.”

Buzz!! Wrong answer!

You could be one move away from solving it. Just turn the cube to match the last rows.

]]>So if any 2 configurations can be transformed in 17 moves then what if one of those 2 is a solved cube? This says that a solved cube maps onto any configuration with only 17 moves.

Perhaps that old proof was shown to be invalid.

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