CPLS

From Speedsolving.com Wiki
Revision as of 21:34, 18 April 2011 by Macky (talk | contribs)
CPLS method
Information about the method
Proposer(s): Baian Liu, ?, ?
Proposed: 2009?
Alt Names: none
Variants: none
No. Steps: 1
No. Algs: 26
Avg Moves: ~10
Purpose(s):


CPLS (short for Corner Permutation and Last Slot) is a substep used to solve the final F2L corner (usually DFR) and permute the last-layer corners while preserving the corresponding edge and EOLL. If used when only the last F2L corner, EPLL, CPLL, and COLL remain, CPLS leaves just EPLL and COLL, which may be solved using 2-generator. Although seemingly hard to recognize, CPLS can be very beneficial, especially for one-handed solvers if fast 2-generator algorithms are used.

A two-step solution to EPLL and COLL requires only 11 algorithms: 7 for OCLL, which leaves 4 EPLL cases. One-step solution, known as 2GLL, has 84 cases. Note that this is also referred to as ZZ-d.

Learning Approach

CPLS is naturally divided into the subsets - +, O, I, Im, and C, the same classification used for CLS. The first three sets have 6 algorithms each, the next two have 3 each, and the final set has only 2. One recommended order, for ease of learning and recognition, is C, O, I, Im, -, +.

Recognition

Recognition is definitely the most prominent downfall to this method, at least in terms of personally finding an intuitive way to do so. However, a system has been found that works very well.

Before you start, it must be emphasized that you *must* know your color scheme fairly well.

Let's set up a case. Do x R' U R U' R' U R U' R' U R U' x' onto a scrambled cube with yellow on top and red on front.

Seeing this, I know that this is an O case, and that it's already positioned correctly, in URF, to be recognized.

Next, I need to look at the remaining three U-layer pieces.

Let's keep a system to *always* start with UFL.

Once reaching any of the three corners, in this order, the first goal is to locate the U-layer sticker, in my case yellow. This should be on the top for this case.

Next, look at the sticker *clockwise* from this sticker. In other words, the sticker on the F face, or the FLU sticker. This should be red. I note this, and that my red FACE is currently on B. I now pretend that the entire F face is orange, because when rotated, that sticker lies on that face.

Following that, do the same for the LUB and BRU corners.

For the L face, you should come out with green, since the sticker at LUB is green.

For the B face, you should come out with orange, since the sticker at BRU is orange.

One could write this case down as an [O BLF], being as though B is on F, L is on L, and F is on B. Depending on initial AUF, however, this may change

So, from the above, we can visualize that F = red, L = green, and B = orange. Knowing that yellow is our U-layer sticker, we know that the above can't be right - those colors aren't allowed to be like that! So what we must do is switch those "face." To do this, we must switch the corners that these pieces are represented by. For example, the UFL piece represents the Front face. In this case, we must switch the UFL and UBR corners. To understand what to do now, we go over to https://sites.google.com/site/devastatingspeed/3x3x3/cpls and try to find the right case. Knowing that we have a diagonal switch (switching UFL and UBR has essentially the same effect as switching UFR and UBL), we look for the O case with the diagonal swap, which is in the 3rd row, second column, yielding us the algorithm x (U R' U' R)*3 x'

After applying this, the F2L should be finished, and the LL should be reduced to a 2GLL case, to be done in however many steps. More than two steps makes CPLS very unnecesarry and arguably a waste of time, though.

Example Solves

This recognition method is best illustrated with example solves. Standard color scheme is assumed throughout. Scramble with white on top (U) and green in front (F).

Scramble 1: D' B' D2 F2 R F' L' R B L' F' U' R' B F2 U R2 D L2 D2 U' B R' F2 D'

A Petrus approach

2x2x2: x2 D B' R' D2 L2 (5/5)
2x2x3: x' y D R D' U' L' U L (7/12) -note that this sets up for an Im case later on.
EO: y U M' U M (4/16)
F2L: x y U2 R' U' R U R' U' R2 U2 R' (10/26) [ewww]
CPLS (Im FBL): y2 U R' F2 R D' L' U2 L' U' L2 D (11/37)
2GLL (Pi Ua1): y (y) R U2 R2 U2 R U R2 U R2 U' R2 U2 R' U2 R(16/53)
AUF: U2 (1/54)


Scramble 2: L2 F' L2 F L' D B D2 U2 L2 D L' R B' L2 U B2 R2 D2 R B2 D U2 B' F'

A RH OH ZZ approach

EOCross: L B' R' U D F R D R' D R' (11/11)
BL slot: U2 R U R' L U L' (7/18)
FL slot: L2 U2 L U L' U L2 (7/25)
BR slot: U R' U' R U' R' U R (8/33)
FR edge: R U R' (3/36) [gah, it kills me not to do CLS for this case :(]
CPLS setup: U2 (1/37)
CPLS (O): y U2 z' U L' D2 L U' L' D2 z (8/45)
2GLL (T Ub2): z' U L2 U' L' U L' U' L U L U' L U L2 U' (15/60)
AUF: L2 (1/61, or 57 with cancellations)

Scramble 3: L' R' B F U B2 D2 F2 L F2 D U' B' U D2 F2 B L2 R2 B U2 B' D2 U2 R

A CFOP approach

Cross: x2 F D L2 U2 L F' (6/6)
BL slot: F' U2 F L U' L' (6/12)
FR slot: U R U2 R' U R' F R F' (9/21)
BR slot: U' R' U2 R2 B R B' (7/28)
ELS setup: y U (1/29)
ELS: R U' R' F' U2 F (6/35)
CPLS (+): U' U' y R' U L' U' R U L (9/44) 	
2GLL (Pi Ub3): y' (y) R U2 R2 U' R' U R U' R' U' R' U' R' U2 R U2 (15/59, or 56 with cancellations)

See Also

External Links