Difference between revisions of "Petrus Method"

From Speedsolving.com Wiki
(37 intermediate revisions by 16 users not shown)
Line 5: Line 5:
 
|year=1981
 
|year=1981
 
|anames
 
|anames
 +
|algs=2 to 493 (for the last layer)
 
|variants
 
|variants
 
|steps=7
 
|steps=7
|moves=45 to 60
+
|moves=~50
 
|purpose=<sup></sup>
 
|purpose=<sup></sup>
 
* [[Fewest Moves]]
 
* [[Fewest Moves]]
 
* [[Speedsolving]]
 
* [[Speedsolving]]
 
}}
 
}}
The '''Petrus Method''', invented by [[Lars Petrus]], is a block-building [[method]] where the [[F2L]] is solved intuitively with no [[algorithm]]s. Behind [[Fridrich]], it is currently the second most popular speed cubing method in use.
+
 
 +
{{Method Header
 +
|listofsteps=[[2x2x2 Block]] -> [[2x2x3 Block]] -> [[EO Petrus]] -> [[Petrus F2L]] -> [[LL+EO:CP]] -> [[LL+EO+CP:CO]] -> [[EPLL]]
 +
|description='''Petrus''' was the second most popular speedcubing method behind [[CFOP]].
 +
}}
 +
 
 +
The '''Petrus Method''', invented by [[Lars Petrus]], is a block-building [[method]] where the [[F2L]] is solved intuitively with no [[algorithm]]s. Petrus was the second most popular speedcubing method behind [[Fridrich]]/[[CFOP]]; however other methods like [[ZZ]] and [[Roux]] are currently more popular.
 +
 
 +
The Petrus Method is sometimes partially used in [[CFOP]] solves for [[XCross]].
  
 
== The Steps ==
 
== The Steps ==
 +
The following steps describe an approach suited for beginners, more advanced users might combine steps 1 and 2 and/or 5 and 6 ([[COLL]]) or use a [[Fridrich]] type last layer and do [[OLL]] and then [[PLL]]. If the fifth step is skipped the last layer can be solved with a [[2GLL]] algorithm.
  
1. First, build a 2x2x2 block anywhere on the cube.
 
  
2. Next, you expand the 2x2x2 block to a 2x2x3 block.
+
1. Build a [[2x2x2 block]] anywhere on the cube.
  
3. After that, you fix the "bad edges" or orient the remaining seven edges on the cube that have not been solved.
+
2. Expand the [[2x2x2 block]] to a [[2x2x3 block]]; three ways are possible.
  
4. Then, you finish the First Two Layers (F2L). The pure Petrus approach is to create a 1x2x2 block and expand it to a 1x2x3 block to finish off the F2L, not to solve the cross piece and two corner/edge pairs.
+
3. Fix the "bad edges" (in other words, orientate the remaining seven edges on the cube that have not been solved).
  
5. Next, you permute the last layer corners, or put them in their proper places (they do not have to be oriented.)
+
4. Finish the First Two Layers (F2L) by only turning 2 sides. The pure Petrus approach is to create a 1x2x2 block and expand it to a 1x2x3 block to finish off the F2L, not to solve the cross piece and two corner/edge pairs; two ways are possible. The last-layer edges will orientate themselves automatically.
  
6. Now, you orient the last layer corners, making the whole last layer a solid color.
+
5. Permutate the last-layer corners (put them in their correct places).
  
7. Finally, you permute the last layer edges, without disturbing anything else, to solve the cube.
+
6. Orientate the last-layer corners, making the whole last layer a solid colour.
 +
 
 +
7. Permutate the last layer edges, without disturbing the other pieces, to solve the cube.
  
 
== Pros ==
 
== Pros ==
  
The Petrus Method uses fewer moves than the [[Fridrich]] method and most other non-block-building methods. It is more intuitive than the Fridrich method, and it requires far less algorithms.
+
* The Petrus Method uses fewer moves than the [[Fridrich]] method and most, if not all, other non-block-building methods.
 +
* It is more intuitive than the Fridrich method, and it requires far fewer algorithms.
 +
* It requires fewer algorithms than some beginner methods (including the most popular one: [[Layer By Layer]]).
 +
* If [[COLL]] is used as well, one can orientate and permutate the corners at the same time.
 +
* The last layer can even be solved in one look with [[ZBLL]] or [[ZZLL]], however this drastically increases the number of algorithms one must learn.
  
 
== Cons ==
 
== Cons ==
  
It can be sometimes hard (especially for a beginner) to optimize block building, and it's difficult to keep consistently turning throughout the solve.
+
* It can be sometimes hard (especially for a beginner) to optimize block building, and it's difficult to keep consistently turning throughout the solve.
 +
 
 +
* Due to the high amount of intuition, it is difficult to optimize finger tricks during the block building stage.
 +
 
 +
* Recognition in the Edge Orientation step tends to result in long pauses.
  
 
== Petrus variations ==
 
== Petrus variations ==
  
There are several other [[sub step|substeps]] that can be used [[EJLS]], [[WV]], [[COLL]], [[JSLS]], and [[ZBLL]], which completes the entire last layer in a single algorithm.
+
There are several other [[substep]]s that can be used [[EJLS]], [[WV]], [[COLL]], and [[ZBLL]], which completes the entire last layer in a single algorithm.
  
 
== Petrus as a Beginner Method ==
 
== Petrus as a Beginner Method ==
 +
 
Used as a beginner method, Petrus requires much more intuition, but also involves learning fewer algorithms. For a tutorial, see the external links below.
 
Used as a beginner method, Petrus requires much more intuition, but also involves learning fewer algorithms. For a tutorial, see the external links below.
  
== External Links ==
+
== External links ==
  
 
* [http://lar5.com/cube/ Lars Petrus's tutorial]
 
* [http://lar5.com/cube/ Lars Petrus's tutorial]
Line 53: Line 73:
 
* YouTube: [http://www.youtube.com/watch?v=WqXdO2H2FTs Petrus Tutorial] by CuberChris
 
* YouTube: [http://www.youtube.com/watch?v=WqXdO2H2FTs Petrus Tutorial] by CuberChris
  
[[Category:Methods]]
+
 
[[Category:3x3x3 Methods]]
+
[[Category:3x3x3 methods]]
[[Category:3x3x3 Beginner Methods]]
+
[[Category:3x3x3 beginner methods]]
[[Category:3x3x3 Speedsolving Methods]]
+
[[Category:3x3x3 speedsolving methods]]
 
[[Category:Fewest Moves Methods]]
 
[[Category:Fewest Moves Methods]]

Revision as of 12:35, 9 April 2017

Petrus method
Petrus method.gif
Information about the method
Proposer(s): Lars Petrus
Proposed: 1981
Alt Names: none
Variants: none
No. Steps: 7
No. Algs: 2 to 493 (for the last layer)
Avg Moves: ~50
Purpose(s):


Scramble 04.jpg

Scrambled cube -> 2x2x2 Block -> 2x2x3 Block -> EO Petrus -> Petrus F2L -> LL+EO:CP -> LL+EO+CP:CO -> EPLL -> Solved cube


Petrus was the second most popular speedcubing method behind CFOP.

Mini maru.jpg

The Petrus Method, invented by Lars Petrus, is a block-building method where the F2L is solved intuitively with no algorithms. Petrus was the second most popular speedcubing method behind Fridrich/CFOP; however other methods like ZZ and Roux are currently more popular.

The Petrus Method is sometimes partially used in CFOP solves for XCross.

The Steps

The following steps describe an approach suited for beginners, more advanced users might combine steps 1 and 2 and/or 5 and 6 (COLL) or use a Fridrich type last layer and do OLL and then PLL. If the fifth step is skipped the last layer can be solved with a 2GLL algorithm.


1. Build a 2x2x2 block anywhere on the cube.

2. Expand the 2x2x2 block to a 2x2x3 block; three ways are possible.

3. Fix the "bad edges" (in other words, orientate the remaining seven edges on the cube that have not been solved).

4. Finish the First Two Layers (F2L) by only turning 2 sides. The pure Petrus approach is to create a 1x2x2 block and expand it to a 1x2x3 block to finish off the F2L, not to solve the cross piece and two corner/edge pairs; two ways are possible. The last-layer edges will orientate themselves automatically.

5. Permutate the last-layer corners (put them in their correct places).

6. Orientate the last-layer corners, making the whole last layer a solid colour.

7. Permutate the last layer edges, without disturbing the other pieces, to solve the cube.

Pros

  • The Petrus Method uses fewer moves than the Fridrich method and most, if not all, other non-block-building methods.
  • It is more intuitive than the Fridrich method, and it requires far fewer algorithms.
  • It requires fewer algorithms than some beginner methods (including the most popular one: Layer By Layer).
  • If COLL is used as well, one can orientate and permutate the corners at the same time.
  • The last layer can even be solved in one look with ZBLL or ZZLL, however this drastically increases the number of algorithms one must learn.

Cons

  • It can be sometimes hard (especially for a beginner) to optimize block building, and it's difficult to keep consistently turning throughout the solve.
  • Due to the high amount of intuition, it is difficult to optimize finger tricks during the block building stage.
  • Recognition in the Edge Orientation step tends to result in long pauses.

Petrus variations

There are several other substeps that can be used EJLS, WV, COLL, and ZBLL, which completes the entire last layer in a single algorithm.

Petrus as a Beginner Method

Used as a beginner method, Petrus requires much more intuition, but also involves learning fewer algorithms. For a tutorial, see the external links below.

External links