The other day, having nothing to do, I started optimizing my
transformations. Counting 90-degree twist, 180-degree twist and a
twist of the middle slice as a single move, I reached the following
numbers: for Plummer cross: 24 moves, and for what I call inverting
the cube (that means flipping every non-corner cubie) 29 moves. Now
realizing that neither of those comes close to the optimum # of moves,
I'd like to know how far of the so far achieved optimum am I?