Difference between revisions of "ZZ method"

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== See Also ==
 
== See Also ==
 
* [[EOLine]]
 
* [[EOLine]]
 +
* [[Edge Orientation]]
 
* [[ZZ-blah]]
 
* [[ZZ-blah]]
 
* [[ZBLL]]
 
* [[ZBLL]]

Revision as of 16:13, 12 October 2009

ZZ method
Eoline.gif
Information about the method
Proposer(s): Zbigniew Zborowski
Proposed: 2006
Alt Names:
Variants: ZZ-VH, ZZ-a, ZZ-b, ZZ-c, ZZ-d, ZZ-WV, MGLS-Z, EJLS
No. Steps: 3 or 4 (depending on LL)
No. Algs: 20 to 537
F2L: 0 to 40
LL: 20 to 497
Avg Moves: 44 to 50 depending on varient
Purpose(s):


The ZZ method was created by Zbigniew Zborowski in 2006. The method is focused both on low move count and high turning speed; during the majority of F2L, the solver only needs to make L, U, and R moves, which means that the solver's hands never leave the left and right sides of the cube, resulting in faster solving. In addition, edges are already oriented when the solver reaches the last layer, meaning the solver has fewer cases to deal with.

The Steps

  • EOLine: This is the most distinctive part of the ZZ method. In this step, the solver orients all the edges while placing the DF and DB edges. The two edges and the bottom centre are the "line" in EOLine. This step puts the cube into an <L, U, R> group, meaning F, B, or D moves are not required for the remainder of the solve. Although this step may seem like a hinderance, it speeds up the F2L and LL.
  • F2L: The solver creates a 2x3x1 block on each side of the line via blockbuilding. Because one only needs to do L, U, and R moves, solving is very quick.
  • LL: The solver uses algorithms to solve the remaining pieces. Since the edges in the LL were oriented during EOLine, it can be completed in fewer moves and/or with fewer algorithms to learn.

Variants

There are several variations of the ZZ method, each of which treats the F2L and LL differently:

  • ZZ-VH: This is the simplest variety of the ZZ method. The F2L and LL are completely separate; no special techniques are used to make the LL easier during F2L. One can do the LL in two steps by doing OCLL/PLL or COLL/EPLL.
  • ZZ-a: This completes the last layer in a single step, also known as 1LLL (one-look last layer). There are 494 cases, solvable by 177 algorithms, in an average of ~12.08 moves. The algorithms used are the same as ZBLL.
  • ZZ-b: During F2L, the solver employs a technique called Phasing to correctly permute two LL edges. Before the last corner-edge pair is placed, the solver uses one of several algorithms depending on how the edges are positioned. The last layer is then completed with one look using ZZLL.
  • ZZ-c: The last layer corners are solved during insertion of the last F2L block. This system is similar to using Winter Variation, but can be applied to any last block situation and uses more algorithms. Conceptually, the comparison of ZZ-c with ZZ-WV, is similar to the comparison of ZBF2L with VH.
  • ZZ-d: This variation is almost impossible to use for speed solving. Before the completion of the first F2L block, the solver permutes the remaining corners to put the cube into an <R, U> group. This makes the rest of the solve 2-gen, which is even faster than 3-gen. Only a maximum of 2 additional moves are required to correctly permute the corners. However, the solver must determine the permutation of all the unsolved corners to execute this step; this is a slow process, hence ZZ-d is not appropriate for speed solving.
  • ZZ-WV: Before the last corner-edge pair is placed, the solver correctly orients all the corners by using 1 of 27 algorithms. This technique is called F2LL. After the first two layers, the solver is left with a PLL case, since both edges and corners are oriented.

Pros

  • Ergonomics: F2L is completed using only R, U and L turns and no cube rotations are required.
  • Lookahead: Pre-orientation of edges halves the F2L cases and makes edges easier to find and connect to blocks/corners. During a ZZ solve, the cube is typically held in the same orientation through out the solve which allows a memory map of pieces' correct locations to develop allowing fast/intuitive ability to place pieces without thinking/looking.
  • Efficiency: With a blockbuilding-based F2L and pre-orientation of LL edges around 55 moves can be achieved without difficulty. Optimising F2L blokbuilding and adoption of more advanced LL systems such as ZBLL will reduce this move count significantly.
  • Ease of Learning: Most of the difficulty in ZZ is confined to the EOLine stage. Intuitive blockbuilding during F2L is fairly easy to pick up and only 20 algorithms (assuming use of mirrors) are required to achieve a 2-look last layer with OCLL/PLL.
  • Flexibility: With edges pre-oriented many systems exist for completing the last layer in a ZZ solve, ranging from OCLL/PLL to ZBLL. A blockbuilding F2L also allows for the development of many short cuts and tricks as skill improves.

Cons

  • Reliance on Preinspection - ZZ makes heavy use of preinspection time, which is fine where 15sec is given, but in situations where no preinspection is used it can be a drawback. For example, using reduction on big cubes, or in multi-solve scenarios.
  • Difficulty of Transition from Fridrich - Solving EOLine and a blockbuilding F2L is very different from Fridrich Cross and slot-based F2L. The possibility of using cross and a slot-based F2L can make it difficult to shake off old habits.
  • Difficulty of EOLine - EOLine is difficult to plan and execute in one step and takes a long time to master. New users should expect it to take in the order of months to achieve full EOLine inspection in 15 seconds. In the interim, breaking it down into two steps (EO + Line) can be used as a fall-back.
  • 2 Extra F2L Cubies to Solve The first step of Fridrich (Cross) and ZZ (EOLine) are roughly comparable in terms of move-count. The remainder of F2L in ZZ requires solving of two more cubies (10 in total) than Fridrich slots (8 in total). However, freedom to fully rotate the L and R faces and the use of more efficient block building compensates for this apparent disadvantage.

See Also

External Links