Corner Orientation
|
|
Information
|
Proposer(s):
|
|
Proposed:
|
|
Alt Names:
|
CO
|
Variants:
|
OCLL
|
Subgroup:
|
|
No. Algs:
|
7
|
Avg Moves:
|
|
Purpose(s):
|
|
|
Corner Orientation, abbreviated CO, the orientation of a cube's corners. There are three possible corner cubie orientations. CO is a substep in many methods.
For the last layer of the 3x3x3 cube there are three main variations used for the seven cases of CO, one that is named pure CO which orients the corners without affecting anything else, not even corner permutation, one preserves edge orientation which is OCLL (OLL 21 - 27) and the last variation orients the corners ignoring edges (use any OLL that twists the same corners for that).
The separation of the corners to their correct layers on the Square-1 is often wrongly named "corner orientation".
Algorithms; at this page you can find algorithms for two different variations of CO;
- Pure CO: orients corners preserving edge orientation and both corner and edge permutation.
- OCLL-EPP: orients corners preserving edge orientation and permutation for the edges but not the corners (this method is seldom used).
See also
Pure CO
Usage: Besides that these cases are a group in L4C, L3C, ZBLL, ZZLL;
3OP is a blindfold method that orients the pieces before they are placed into position, the algorithms here solves the corner orientation in at the most 3 steps, first, if needed two pieces, one in the top layer and one in the bottom layer to fix orientation parity and then 2-4 corners in the top layer and then the same for the bottom layer. Algs for pure orientation of the edges can be found at the ELL page.
Any other BLD method, to fix orientation for corners that are in position but unoriented from the scramble (a few setup moves to get the pieces into the same layer may be needed then).
For FMC to solve the last pieces (but that won't give any WR, better to try some different start of the last layer that gives a easier case in the end).
Algorithms
All cases here have long algorithms, the H case is actually the worst LL case of them all and the Pi case is second worst. The good thing is that all cases are solvable using only two sides (RU 2-gen). There are different sections for different types of algorithms, first is optimal 2-gen followed by 2-gens of any length. All cases can be solved using two or more Sune, the third section is for these combinations (double, anti and mirrors included). Next comes algs optimal in Half Turn Metric, using as many sides that is needed for that (2-6) and the last section is for any other alg that solves the case.
Note that all of these algorithms are written in the Western notation, where a lowercase letter means a double-layer turn and rotations are denoted by x, y, and z. (how to add algorithms)
Click on an algorithm (not the camera icon) to watch an animation of it.
|
Two corners unoriented
Note that the T-twist is the same case as the U-twist if you reorient the cube (for these images that will be z' y2).
U
Optimal 2-gen:
Any other 2-gen:
Sune combos:
HTM optimal:
Any other:
|
T
Optimal 2-gen:
Any other 2-gen:
Sune combos:
HTM optimal:
Any other:
|
L
|
Name: L, Bowtie
Used in: L3C, L4C, BLD
Optimal moves: 12 HTM
|
Optimal 2-gen:
Any other 2-gen:
Sune combos:
HTM optimal: (12 move commutator)
Any other:
|
|
Three corners unoriented
S
Optimal 2-gen:
Any other 2-gen:
Sune combos:
HTM optimal:
Any other:
|
-S
|
Name: -S, Antisune
Used in: L3C, L4C, BLD
Optimal moves: 13 HTM
|
Optimal 2-gen:
Any other 2-gen:
Sune combos:
HTM optimal:
Any other:
|
Four corners unoriented
H
|
Name: H
Used in: L4C, BLD
Optimal moves: 16 HTM
|
Optimal 2-gen:
Any other 2-gen:
Sune combos:
|
Alg
|
!
|
|
HTM optimal:
Any other:
|
Pi
|
Name: pi, Bruno
Used in: L4C, BLD
Optimal moves: 15 HTM
|
Optimal 2-gen:
Any other 2-gen:
Sune combos:
|
Alg
|
!
|
|
HTM optimal:
Any other:
|
OCLL-EPP
Orientation of the corners of the last layer - edges permutation preserved; orients the last layer corners preserving edge permutation but ignoring corner permutation.
Usage; to solve the last four corners in two looks if the edges are solved (3-look LLEF, OCLL-EPP and CPLL, total 26 algs. 4-look EO, EP, OCLL-EPP and CPLL, total 16 algs).
Average movecount is 9.63 turns optimally, CPLL is 9.12 turns optimally which gives 19 moves on average for solving L4C in 2-looks like this.
Algorithms
Note that all of these algorithms are written in the Western notation, where a lowercase letter means a double-layer turn and rotations are denoted by x, y, and z. (how to add algorithms)
Click on an algorithm (not the camera icon) to watch an animation of it.
|
Two corners
U (EPP)
|
Name: U, Headlights, Superman
Used in: 2-look L4C
Optimal moves: 9 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
T (EPP)
|
Name: T
Used in: 2-look L4C
Optimal moves: 8 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
L (EPP)
|
Name: L, Bowtie
Used in: 2-look L4C
Optimal moves: 8 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
|
Three corners
S (EPP)
|
Name: S, Sune
Used in: 2-look L4C
Optimal moves: 8 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
Alg
|
!
|
|
|
-S (EPP)
|
Name: -S, Antisune
Used in: 2-look L4C
Optimal moves: 8 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
Alg
|
!
|
|
|
Four corners
H (EPP)
|
Name: H
Used in: 2-look L4C
Optimal moves: 12 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
Pi (EPP)
|
Name: pi, Bruno
Used in: 2-look L4C
Optimal moves: 12 HTM
|
Optimal 2-gen:
HTM optimal:
Any other:
|
OLC Algorithms
Orient Last Corners (OLC), also known as Orient Last 4 Corners (OL4C), is a subset of OLL used in ZZ-reduction following Phasing that orients corners while preserving edge permutation (2 opposite edges or all 4). This results in a limited PLL set of 9 cases, down from 21 in full PLL. If you permute all four edges every time (superphase) and employ OLCs that preserve full edge permutation, this further reduces PLL cases to just A, E, and H.
Of the 7 orientation cases in ZZ, 4 do not commonly preserve edge permutation (Sune, Antisune, Pi, Double-Sune). The other 3 commonly preserve edges (Headlights, Chameleon, Triple-Sune).
Odds of skipping this step are 1/27.
Note that all of these algorithms are written in the Western notation, where a lowercase letter means a double-layer turn and rotations are denoted by x, y, and z. (how to add algorithms)
Click on an algorithm (not the camera icon) to watch an animation of it.
|
OLC 1
Probability 4/27
|
Name: S, Sune, Swimming Left
Used in: ZZ-reduction
Optimal moves: {{{optimal}}}
|
Preserves All Edges (for superphasing)
OLC 2
Probability 4/27
|
Name: -S, Antisune, Swimming Right
Used in: ZZ-reduction
Optimal moves: ? HTM
|
Preserves All Edges (for superphasing)
Preserves Parity Only
OLC 3
Probability 2/27
Preserves All Edges (for superphasing)
Preserves Parity Only
OLC 4
Probability 4/27
Preserves All Edges (for superphasing)
Preserves Parity Only
OLC 5 (OLL 23)
Probability 4/27
Preserves All Edges (for superphasing)
Preserves Parity Only
OLC 6 (OLL 24)
Probability 4/27
|
Name: T, chameleon, shark, Hammerhead, Little Horse, stingray
Used in: ZZ-reduction, OCLL, OLL
Optimal moves: 8 HTM
|
Preserves All Edges (for superphasing)
Preserves Parity Only
OLC 7 (OLL 25)
Probability 4/27
|
Name: L, Bowtie, Triple-Sune, Side-winder, Diagonals, Spaceship
Used in: ZZ-reduction, OCLL, OLL
Optimal moves: 8 HTM
|
Preserves All Edges (for superphasing)
Preserves Parity Only