3x3 · COLL
3x3 COLL U 2 algorithm
3x3 COLL U 2 algorithm: 19 turns, opening with R' F R. Case recognition, the complete sequence, and practical execution notes.
Solve the last-layer corners with the last-layer edges already oriented; edge permutation may remain.
U 2 belongs to the U group in COLL.
Recognize this starting position
In the inverse-derived training position, the upper-face color points upward at these corner positions: UFR, UFL. Upper edges with that color facing up: UF, UL, UB, UR. Reading each side’s upper corner stickers left to right when facing that side gives F: F F; R: R L; B: U U; L: R L. The letters identify colors by their reference faces.
Execute the algorithm
R' F R U' R' U' R U R' F' R U R' U' R' F R F' R
The opening is R' F R; the final segment is R F' R. This version contains 19 face, wide, or slice turns and no whole-puzzle rotations.