4x4 Parity ((full))

The root cause lies in the . On a 3x3, the center pieces are fixed, defining the color of each face and the possible paths for edges. On a 4x4, the "centers" are actually four independent pieces that can be swapped around. When we "reduce" the cube, we might accidentally swap two internal pieces or "hidden" orbits, leading to a state that looks fine to us but is mathematically inverted relative to a 3x3. Tips for Handling Parity

2R2 U2 2R2 Uw2 2R2 Uw2

After this, your last layer should have a normal OLL case. You may need to re-orient or re-perform OLL, but no parity will remain. 4x4 parity