# X-CROSS can you do it?



## yangzhengbao (Jul 9, 2010)

X-CROSS 必要性分析（上篇）
2010-07-08 17:19
第一个：B' F' L R2 B2 R' B2 R B' F L R B2 U2 B L B U' R B F2 R' D2 B R'

XCROSS：R' F2 B' D2 R U' L2 B'

F2L2：L'ULU'L'UL

F2L3: U'R'U'RUR'U'RUy'L'U'L

F2L4: U2LUL'U2LU'L'

CF=36

OLL：U'(r' F' U F) (L F' L' U' r)

PLL:U R' U R' U' y R' F' R2 U' R' U R' F R F U

第二个：L2 U' L' R2 B L2 R2 F' L F' U2 B F2 R2 U2 B L R2 U R2 D2 F2 L U2 L2

XCROSS：U2 D' L F' D' F' D2 L D2

F2L2：U'R'U'RU2LUL'

F2L3: LUL'UL'U'L

F2L4:yU2RUR'U2RU'R'

CF=33

OLL:U (R'U'R U)y(r U R' U')r' R

PLLR U R'F')(R U R'U')(R'F R2 U'R')

第三个：F' L U F2 R2 B' F U L2 B2 F D' L B F2 D2 L B2 D U' L' D2 F2 D' U

XCROSS：F' R' U F L' U2 B' D' 

F2L2: U L'U2LU'R'U'R

F2L3: y'U'L'U'LU'LUL'

F2L4: (R U' R' U) (R' F R F') R U' R'

CF=36

OLL: U' (r R'2 U' R U')(R' U2 R U' R)r'

PLLR U' R)(U R U R)(U' R' U' R2)U'

第四个：L' F2 D' U L' R F2 D' U' L' F2 L B' F2 L R D' U B F2 D' B' U' B F


XCROSS：R B D2 B2 U D R F

F2L2：y'LU2L2U'L

F2L3: RU2R'dR'UR(题外话：转了个d看见了LF空槽！)

F2L4:L'ULU'L'UL

CF=27

OLL：f (R U R' U')2 f'

PLL: x'(R U' R)z'(R'2 U' L U R2' B2)

第五个：F2 L2 R2 D L F2 L' D' L R' F' U2 R2 F2 L R' U' F2 R D L D2 F2 R D

XCROSS：U F' L' F' D' L F2 U2 R'

F2L2:UL'U'LLUL'ULU'L'

F2L3:R'U'R L'U2L U2 L'UL

F2L4: yRUR'U RUR'

CF=37

OLL:U2(f R U)(R2 U'R' U R2 U' R' f')

PLL:U'(R U R'F')(R U R'U')(R'F R2 U'R'U2


第六个：U' L R' U F' L2 R' B F D' U' L R2 U2 B D' L F D2 U F' L' D' U' L'

XCROSS：B' U2 F' L' D' L' D2 L

F2L2: U2LUL'

F2L3: y'RU2R'UR'U'R'

F2L4: y'U'L'U'LU2L'U2LU2L'UL

CF=33

OLL: U F'(r U R' U')(r' F R)

PLL: U2 x' R2 D2(R' U' R)D2(R' U R')

第七个：D U2 B2 F L' R' B' R' D' R D' B F' D' U2 F2 D U2 F' R2 B' R2 U2 L2 B

XCROSS：U2 R2 L' B R' D R' F

F2L2: U' LU'L'U' R'UR

F2L3: dU2LU'L

F2L4: U2 (R' F R F') U2 R U R'

CF=30

OLL: U' (R U R' U' r)(R' U)(R U' r')

PLL: U (R' U2)( R U) (R' U2) L U' R U L'


第八个：D U R2 B' F D' U L' R' D' L2 R' D2 U B' U' L2 R B2 F R2 B' F' D2 U'

XCROSS：D L' F D' R' U' B2 R2 

F2L2: U LU'L'ULUL'

F2L3: U2R'U2RU'R'UR

F2L4:U2L'U'LU2L'U2LU2L'UL

CF=36

OLL: U2(r U' r'U')(r U r') (F' U F)

PLL: (R U R'F')(R U R'U')(R'F R2 U'R'U2

第九个：B F L' R' B D' L' R' D2 L R2 D L' B' F2 U L2 B2 F2 R2 F2 L' U R2 B2

XCROSS：F' R' D R2 B2 R' L' D 

F2L2: U'L'U'L U2LUL'

F2L3: U L'U'LU'L'UL

F2L4: U2 R'U2RUR'U'R

CF=32

OLL: R' F R U R' F'R (F U' F')

PLL: U (R' U2)( R U) (R' U2) L U' R U L'

第十个 ：D U2 B2 D2 U' F' D2 U' F L R' U2 B2 L2 R2 D' F' L' U R' D2 U2 B2 F' L

XCROSS：U2 L F' D L' F' B' L2 D

F2L2:UR'U2RU'R'UR

F2L3:y' U'RUR'U'RUR'

F2L4:y' U(R' F R F') U2 R U R'

CF=35

OLL:U(r U R' U') (r' F R F')

PLL: U'(R' U2)( R U) (R' U2) L U' R U L'U'

第十一个：F2 U' L2 F2 L2 R B F2 U' F L' R B F2 R B2 F2 D2 U' B F L' D U' F'

XCROSS：U2 F B' U B2 R' U2 F L

F2L2: y' URU'R'

F2L3: U2LU'Ly'L'U2L

F2L4:U(R'FRF')RUR'

CF=30

OLL: U2 r U R' U R U'U' r'

PLL: U (R U R')y'(R2' u' R U')(R' U R' u R2)

第十二个：U F' D U B U2 B L' B' F D2 L' R' B R D2 U2 B F2 L' R2 B F2 D2 U'

XCROSS：D F L U B' R B

F2L2: UL'ULU2L'UL

F2L3: y'LU2L2U'L

F2L4: ULU2L'U2LU'L'

CF=39

OLLR U R' U' r)(R' U)(R U' r')

PLLR2 u)(R' U R' U')(R u') (R2' F' U F)U2

XCROSS条件下CF12平均：（39 30 35 32 36 30 33 37 27 36 33 36）/12=33.67步


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## yangzhengbao (Jul 9, 2010)

1.B' F' L R2 B2 R' B2 R B' F L R B2 U2 B L B U' R B F2 R' D2 B R'

crossz2)U'RFRDF’D2R'

1F2L:U'R'U'RL'UL

2F2L:RU'R'URUR'

3F2L:yU'U'RU'R'y'UR'U'R

4F2L:y'U'L'ULUL'ULU'L'UL

CF=45

O:R2'DR'U2RD'R'U2R'

PR U R' U')(R' F)(R2 U' R' U')(R U R' F')U



2.L2 U' L' R2 B L2 R2 F' L F' U2 B F2 R2 U2 B L R2 U R2 D2 F2 L U2 L2

CROSS: （z2y’）R2DR'UR'2LF'L'

1F2L:y2L'U'LyU'LUL'

2F2L:L'U'Ly'UR'U'R

3F2L:RU'R'U’LU'L'

4F2L:U2F'U'U'FU'RUR'

CF=48

O:U2 R2'DR'U2RD'R'U2R'

PR U' R' U)(R U)( F R U R' U' F' )(R2‘ F R F')U'


3.F' L U F2 R2 B' F U L2 B2 F D' L B F2 D2 L B2 D U' L' D2 F2 D' U

CROSS: (z2）D2LFR2

1F2L:U'U'RU'R'

2F2L:y'2 URUR'U'RUR'U'RUR'

3F2L:U'R'URL'UL

4F2L:U'R'UR'FRF'R

CF=43

O:U’（R U2 R' U'）（ R U R' U') (R U' R')

P:U2(R2' U)(R U R' U')(R' U')(R' U R')U





4.L' F2 D' U L' R F2 D' U' L' F2 L B' F2 L R D' U B F2 D' B' U' B F

CROSSz2y’)ULF'yRFR2u

1F2L:L'ULR'UR

2F2L:ULUL'

3F2L:U'U'RU'R'

4F2L:L'ULU'y'RUR'

CF=30

O:（R U2 R' U'）（ R U R' U') (R U' R')

P:U2(R2' U)(R U R' U')(R' U')(R' U R')U2





5.F2 L2 R2 D L F2 L' D' L R' F' U2 R2 F2 L R' U' F2 R D L D2 F2 R D

CROSS: （z2y)LU'yF'R'F'U'L2u

1F2L:U'L'U2Ly'L'UL

2F2L:U'F'U'FU'RUR'

3F2L:y2U'RUR'U'RUR'U'RUR'

4F2L: y'RU'R'URU'R'

CF=47

O:U2F (R U'R'U'R U) (R' F')

P:F(R U'R' U')(R U R' F')(R U R' U')(R' F R F')U



6.U' L R' U F' L2 R' B F D' U' L R2 U2 B D' L F D2 U F' L' D' U' L'

CROSSz2y)L'R'D'R2Fu'

1F2L:y'U'U'RUR'U'RUR'U'RUR'

2F2L:U'y'RUR'U'RUR'U'RUR'

3F2L:yU'RU'R'UyRU'R'

4F2L:y’UURU'R'

CF=47

O:F'(r U R' U')(r' F R)

p：U'(RU'U')(R'U2)(RB'R'U')(RURBR2'U'



7.D U2 B2 F L' R' B' R' D' R D' B F' D' U2 F2 D U2 F' R2 B' R2 U2 L2 B

CROSSz2)FLD'R'D

1F2L:R'U'U'RU'U'LUL'

2F2L:RU'R'U'RU'R'URU'R'

3F2L:R'URU'R'U'R

4F2L:y'URUR'U2RU'R'

CF=37

O:r'(R2 U R' U)(R U'U' R' U)(r R')

P:U2 (R2 u)(R' U R' U')(R u') (R2' F' U F)


8.D U R2 B' F D' U L' R' D' L2 R' D2 U B' U' L2 R B2 F R2 B' F' D2 U'

CROSS: (z2y2）U'FR'FFL'D'R'u’ 

1F2L：y'2URUR'yU'R'U'R

2F2L:y'R'U'Ry'U'R'UR

3F2L:U2RU'2R'U2RU'R'

4F2L:U'LUL'Uy'L'U'L

CF=47

O:U(R U'U')(R2' F R F') U2(R' F R F')

P:U2F(R U'R' U')(R U R' F')(R U R' U')(R' F R F')U2

9.B F L' R' B D' L' R' D2 L R2 D L' B' F2 U L2 B2 F2 R2 F2 L' U R2 B2

CROSSz2y2)DFR'FLFy'Lu2

1F2L:R'U2RU2LUL'

2F2L:RUR'U'RUR'

3F2L:y’URU'R'Uy'LUL'

4F2L：yUF'U'F

CF=38

OR U R' U')(R' F R F')

P:U'F(R U'R' U')(R U R' F')(R U R' U')(R' F R F')U2

10.D U2 B2 D2 U' F' D2 U' F L R' U2 B2 L2 R2 D' F' L' U R' D2 U2 B2 F' L

CROSS: （z2y2）R'UR'FyR2u2

1F2L:yU’RUR'URU'R'

2F2L:y U’RU'R'UyL'UL

3F2L:RUR'U'RU2R'

4F2L:U2R'URUUyRUR'

CF=42

O：U2 F (R U'R'U'R U) (R' F')

P:U2(RU2)(R'U2)(RB'R'U')(RURBR2'U


11.F2 U' L2 F2 L2 R B F2 U' F L' R B F2 R B2 F2 D2 U' B F L' D U' F'

CROSS: （z2y）LBF2RuR'

1F2L:U'U'L'UL-UL'ULU'L'UL（目的槽是LB槽）

2F2L:U'RU'R'2UR(做个标记)

3F2L:y'U2R'U'RU'R'UR

4F2L：U'L'U2LU2L'UL

CF=41

o：(R' U') R' F R F'(U R)

P：U(R' U2)( R U) (R' U2) L U' R U L'

12.10.19U F' D U B U2 B L' B' F D2 L' R' B R D2 U2 B F2 L' R2 B F2 D2 U'

CROSS: (z2y2）DURFR'2L2D2

1F2L:URUR'

2F2L:y2U(R' F R F') R U' R'

3F2L:U'L'ULU'L'UL

4F2L:U2R'URU2R'UR

CF=36

o：(r' U2)(R U R'U')(R U R'U) r

p：U'x' R2 D2(R' U' R)D2(R' U R')U2


(36 41 42 38 47 37 47 47 30 43 48 45)/12=41.75步


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## nck (Jul 9, 2010)

What this is i don't even.


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## r_517 (Jul 9, 2010)

dont get it


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## jiggy (Jul 9, 2010)

It's a break down of 24 solves, 12 of which were x-cross, 12 of which were full step. The OP then shows that the x-cross cases have, on average, 33.67 moves to a complete F2L against the full step's 41.75 moves. An improvement of ~8 moves is pretty good, but wouldn't necessarily correspond to a faster solve.

This is an interesting idea, but...why?


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## James Ludlow (Jul 9, 2010)

jiggy said:


> It's a break down of 24 solves, 12 of which were x-cross, 12 of which were full step. The OP then shows that the x-cross cases have, on average, 33.67 moves to a complete F2L against the full step's 41.75 moves. An improvement of ~8 moves is pretty good, but wouldn't necessarily correspond to a faster solve.
> 
> This is an interesting idea, but...why?




8 moves is a whole second - or with me, nearly two seconds.

If you can plan an x-cross in the inspection time, surely this is something that should be used. Hasn't Chris Hardwick done work with the x cross?


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## Kirjava (Jul 9, 2010)

Of course an xcross would give a lower movecount. However, I doubt these solutions were produced with 12 seconds of inspection.

In addition, shorter solutions don't necessarily mean faster execution.


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## James Ludlow (Jul 9, 2010)

Kirjava said:


> Of course an xcross would give a lower movecount. However, I doubt these solutions were produced with 12 seconds of inspection.
> 
> In addition, shorter solutions don't necessarily mean faster execution.



Agreed, but if you can find a fingertrick friendly and fast xcross, it would pay to try and find one?


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## Kirjava (Jul 9, 2010)

For sure, that's the whole point of an xcross. If you see a good one, do it. Otherwise it's better to do a normal cross and track the first pair.


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## yangzhengbao (Jul 9, 2010)

Kirjava said:


> Of course an xcross would give a lower movecount. However, I doubt these solutions were produced with 12 seconds of inspection.
> 
> In addition, shorter solutions don't necessarily mean faster execution.



You can do it in x-cross,and then you can do it in cross in the same Scramble。
you can see it is a shorter time。


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## irontwig (Jul 9, 2010)

Kirjava said:


> For sure, that's the whole point of an xcross. If you see a good one, do it. Otherwise it's better to do a normal cross and track the first pair.



Or just start with a 2x2x2.


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## Kirjava (Jul 9, 2010)

A 2x2x2 start is an xcross.


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## CharlesOBlack (Jul 9, 2010)

not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.

Also, I think that a 2x2x2 is a bit different than a cross with a pair inserted. But that's just me.


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## aronpm (Jul 9, 2010)

CharlesOBlack said:


> If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.



Why not?


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## CharlesOBlack (Jul 9, 2010)

Because when you have a 2x2x2, the pieces solved are LF, LFD, DF and DL. When you have a 2x2x3, the pieces solved are the ones above plus LB, LBD and BD.
If you have an Xcross, then the pieces solved are LF, LFD, DF, DL, *RD,* and, in case of a double Xcross, LB, LBD and BD.


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## Hyprul 9-ty2 (Jul 9, 2010)

wat


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## irontwig (Jul 9, 2010)

Kirjava said:


> A 2x2x2 start is an xcross.



Not necessarily, depending on how you continue. Anyway, I only think of a start as an x-cross if you plan the entire thing in inspection, otherwise it's just something I would call block F2L or whatever or just trying not to be stupid and inflexible.


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## nck (Jul 9, 2010)

CharlesOBlack said:


> Because when you have a 2x2x2, the pieces solved are LF, LFD, DF and DL. When you have a 2x2x3, the pieces solved are the ones above plus LB, LBD and BD.
> *If you have an Xcross, then the pieces solved are LF, LFD, DF, DL, RD, *and, in case of a double Xcross, LB, LBD and BD.



What about DB?
I don't see how you can get an Xcross without getting a 2x2x2


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## irontwig (Jul 9, 2010)

nck: You don't think he just simply forgot to write "DB"?


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## CharlesOBlack (Jul 9, 2010)

nck said:


> CharlesOBlack said:
> 
> 
> > Because when you have a 2x2x2, the pieces solved are LF, LFD, DF and DL. When you have a 2x2x3, the pieces solved are the ones above plus LB, LBD and BD.
> ...



Forgot that one.  

You need to get a 2x2x2 to make an Xcross, but you don't need an Xcross to make a 2x2x2. That's my point.

Kirjava said that a 2x2x2 start makes the solve an Xcross, but it doesn't.


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.



That would be a double x-cross.


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## CharlesOBlack (Jul 9, 2010)

PatrickJameson said:


> CharlesOBlack said:
> 
> 
> > not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.
> ...



that's irrelevant to the question.


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## irontwig (Jul 9, 2010)

PatrickJameson said:


> CharlesOBlack said:
> 
> 
> > not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.
> ...



That's just silly, then any solved F2L, regardless of method would be a quadruple x-cross.


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## James Ludlow (Jul 9, 2010)

CharlesOBlack said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



quantify?


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



What question? 

It's all relative to the method you are using. If you're a CFOP kind of guy and you make a 2x2x3 only to finish the cross and continue with F2L, then of course it's a double x-cross.


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## PatrickJameson (Jul 9, 2010)

irontwig said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



An x-cross is simply a pair that is completed and inserted before the cross is finished.


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## CharlesOBlack (Jul 9, 2010)

PatrickJameson said:


> CharlesOBlack said:
> 
> 
> > PatrickJameson said:
> ...



whether or not a 2x2x2 is an xcross.


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## James Ludlow (Jul 9, 2010)

PatrickJameson said:


> CharlesOBlack said:
> 
> 
> > PatrickJameson said:
> ...



I meant as to why it was irrelevant to the question.


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



Then continue reading.


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## CharlesOBlack (Jul 9, 2010)

jamesdeanludlow said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



If you want to know the difference between oranges and apples, would you ask yourself the difference between pears and lemons first?

If you want to know the difference between a 2x2x2 and an Xcross, would you ask yourself what the difference between a 2x2x3 and a double Xcross is?

same question-question relationship.

edit: irony: I just did an Xcross


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## Edward (Jul 9, 2010)

CharlesOBlack said:


> PatrickJameson said:
> 
> 
> > CharlesOBlack said:
> ...



A 2x2x2 is just a 2x2x2. It's not X cross until the other cross pieces are placed.


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> If you want to know the difference between oranges and apples, would you ask yourself the difference between pears and lemons first?
> 
> If you want to know the difference between a 2x2x2 and an Xcross, would you ask yourself what the difference between a 2x2x3 and a double Xcross is?
> 
> same question-question relationship.



lolwut.

Ok so technically, an x-cross is when there's one pair solved with the cross finished(2x2x2 with cross finished). A double x-cross is two pairs and the cross finished. a solve is not considered to have an x-cross unless you solve the 2x2 or the two pairs before you finish the cross.

Therefore, if you are a CFOP person and solve a 2x2x2 first, it will lead to at least an x-cross(possibly a double x-cross).

(and I have no idea where you came up with the idea that x-crosses and double x-crosses are not alike at all)


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## James Ludlow (Jul 9, 2010)

CharlesOBlack said:


> If you want to know the difference between oranges and apples, would you ask yourself the difference between pears and lemons first?



:confused::confused::confused:


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## CharlesOBlack (Jul 9, 2010)

PatrickJameson said:


> CharlesOBlack said:
> 
> 
> > If you want to know the difference between oranges and apples, would you ask yourself the difference between pears and lemons first?
> ...



To make an xcross, you need to build the cross AND the first F2L pair at the same time. If you build the 2x2x2 and then add the rest of the cross, it's a Petrus-turned-Fridrich solve, and if you make the cross and then add the first pair, it's just a normal Fridrich solve.

(x-crosses and double x-crosses are alike, just as apples and pears are both fruits. )


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> (x-crosses and double x-crosses are alike, just as apples and pears are both fruits. )



Uh, more like a slice of an apple vs half of an apple. But alright.


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## James Ludlow (Jul 9, 2010)

CharlesOBlack said:


> To make an xcross, you need to build the cross AND the first F2L pair at the same time. If you build the 2x2x2 and then add the rest of the cross, it's a Petrus-turned-Fridrich solve, and if you make the cross and then add the first pair, it's just a normal Fridrich solve.



Please forgive me if I am wrong, but using scramble [any Oll] L' U' L2 U L B2 R U R'. Starting with R U' R' B2 L2 would give you a double x cross even though you solved the 2x2 block first. Your saying that is false?


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## CharlesOBlack (Jul 9, 2010)

jamesdeanludlow said:


> CharlesOBlack said:
> 
> 
> > To make an xcross, you need to build the cross AND the first F2L pair at the same time. If you build the 2x2x2 and then add the rest of the cross, it's a Petrus-turned-Fridrich solve, and if you make the cross and then add the first pair, it's just a normal Fridrich solve.
> ...



yup, because



CharlesOBlack said:


> To make an xcross, you need to build the cross AND the first F2L pair at the same time. If you build the 2x2x2 and then add the rest of the cross, it's a Petrus-turned-Fridrich solve,[...]


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## James Ludlow (Jul 9, 2010)

CharlesOBlack said:


> jamesdeanludlow said:
> 
> 
> > CharlesOBlack said:
> ...



not if you have any intention of continuing with petrus, and planned for the block to be part of the cross.

Hey, I disagree with your view on this entirely, but I'll leave it at this and I'll agree to differ.

(I'm right though, I think. )


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## CharlesOBlack (Jul 9, 2010)

jamesdeanludlow said:


> CharlesOBlack said:
> 
> 
> > jamesdeanludlow said:
> ...



I don't understand the bolded part.

(hey, it's fun to debate/discuss!  but if you like, just tell me what you mean with the bolded part and we'll leave it at that)


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## Feryll (Jul 9, 2010)

cmhardw said:


> I consider Xcross to be either:
> 1) seeing the direct solve to the Xcross during inspection
> 2) seeing the solve for the 2x2x2 and one other cross edge during inspection, with intention to locate and place the 4th cross edge during the solving phase.
> 3) seeing the solve for the 2x2x2 during inspection while making sure that the solution for the 2x2x2 puts the other 2 cross edges in a "good" position. A good position means easy to solve in relatively few moves.
> ...


I agree with his statements.


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## James Ludlow (Jul 9, 2010)

CharlesOBlack said:


> (hey, it's fun to debate/discuss!  but if you like, just tell me what you mean with the bolded part and we'll leave it at that)



it's a Petrus-turned-Fridrich solve but not if you have no intention of continuing with petrus, and/or planned for the block to be part of the cross. 

I have next to no knowledge of petrus, so if I was to build a 2x2 block then make an x cross, it would definately not be a petrus-turned-cfop solve.

You right though, it is fun to debate/discuss.

Are you a petrus solver by the way?

EDIT - What he said too ^^^^^^^


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## CharlesOBlack (Jul 9, 2010)

jamesdeanludlow said:


> CharlesOBlack said:
> 
> 
> > (hey, it's fun to debate/discuss!  but if you like, just tell me what you mean with the bolded part and we'll leave it at that)
> ...



Naw, I am/was a CFOP solver but now I'm sorta switching to Roux. (haven't decided yet.)

If you have a Petrus-turned-fridrich solve, without any intention of continuing with Petrus, then you just keep doing fridrich, and it's still a Petrus-turned-Fridrich solve...

If you made a 2x2x2 and then you added the rest of the cross, it'd be a Petrus-turned fridrich solve though, no matter what (according to my view)

also, I believe it's possible to have an unintentional Xcross.


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## nck (Jul 9, 2010)

Petrus turned Fridrich? Would you call a 1x2x3→2x2x3 Roux-turned-Petrus?
I think most people would agree that block-building f2l and eo are more characteristic features of petrus than just a 2x2x2.
Technically. finishing f2l without one cross piece and adding it in at the end would be called a 'quadruple xcross' regardless of whether people choose to do it or not.
IMO if your building 2x2x2 with the intention of adding in the remaining cross pieces and solve f2l in slots, then it would be an Xcross instead of Petrus-turned-Fridrich. It's the same reason why you don't call EO-cross a ZZ-turned-Fridrich.


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## CharlesOBlack (Jul 9, 2010)

nck said:


> Petrus turned Fridrich? Would you call a 1x2x3→2x2x3 Roux-turned-Petrus?
> I think most people would agree that block-building f2l and eo are more characteristic features of petrus than just a 2x2x2.
> Technically. finishing f2l without one cross piece and adding it in at the end would be called a 'quadruple xcross' regardless of whether people choose to do it or not.
> IMO if your building 2x2x2 with the intention of adding in the remaining cross pieces and solve f2l in slots, then it would be an Xcross instead of Petrus-turned-Fridrich. It's the same reason why you don't call EO-cross a ZZ-turned-Fridrich.



in your opinion. 

I'm analyzing the facts, not the intentions.


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## Ranzha (Jul 9, 2010)

First scramble:

Double x-cross: z2 x U R D' F2 L2 U F' U' D R' U [11/11]
F2L3: x’ U2 L U L’ [4/15]
F2L4: U R’ U’ R [U’ y] R U R’ [8/23]
CLL: F R U R’ U’ R U R’ U’ R U R’ U’ F’ [14/37]
ELL: M2 U F2 U M U’ F2 M2 U’ M’ [10/47].
47 moves, STM.
I got lucky there. Those two pairs were BEGGING me to make x-crosses.

EDIT: Btdubs, I wanted to put in the first pair, but halfway I saw the other already connected. Ftw!


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## nck (Jul 9, 2010)

CharlesOBlack said:


> nck said:
> 
> 
> > Petrus turned Fridrich? Would you call a 1x2x3→2x2x3 Roux-turned-Petrus?
> ...



Facts?
Maybe I'm too dumb to find a 'definition' of a 'Petrus-turned-Fridrich'.

or maybe we should just get rid of the term Xcross and replace it by 'Petrus block'


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## CharlesOBlack (Jul 9, 2010)

Ranzha V. Emodrach said:


> First scramble:
> 
> Double x-cross: z2 x U R D' F2 L2 U F' U' D R' U [11/11]
> F2L3: x’ U2 L U L’ [4/15]
> ...



fastest 1x2x3 block I've ever seen


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## Escher (Jul 9, 2010)

@CharlesOBlack: 2x2x2 start =/= Petrus. All it does is exclude you from doing a literal 'CFOP' or 'Roux' solve. The 'substeps' of x-cross don't really matter, the point is that you see more than just the cross in pre-inspection.


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## Kirjava (Jul 9, 2010)

CharlesOBlack said:


> not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.





irontwig said:


> Kirjava said:
> 
> 
> > A 2x2x2 start is an xcross.
> ...





CharlesOBlack said:


> Kirjava said that a 2x2x2 start makes the solve an Xcross, but it doesn't.




This is assuming you're using CFOP - which is what this thread is about. 

I had no idea you guys would suddenly decide that this thread was about FreeFOP for the sake of proving me 'wrong'.

Apparently what I see as obvious/redundant you pedants see as vital, so to refactor my statement-

A 2x2x2 start to a solve using the CFOP method is an xcross.

EDIT;



CharlesOBlack said:


> If you made a 2x2x2 and then you added the rest of the cross, it'd be a Petrus-turned fridrich solve though, no matter what (according to my view)




You don't know what an xcross is.


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## CharlesOBlack (Jul 9, 2010)

Kirjava said:


> CharlesOBlack said:
> 
> 
> > not necessarily. If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore.
> ...



according to chris. According to me, I know perfectly what an xcross is.



Spoiler



hint: this is one of those things that don't ever have a good ending to either party, just like discussing religion


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## Escher (Jul 9, 2010)

CharlesOBlack said:


> according to chris. According to me, I know perfectly what an xcross is.
> 
> 
> 
> ...



Not really, it's more like just blank refusing to accept the standard (right) way of understanding terminology.


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## PatrickJameson (Jul 9, 2010)

CharlesOBlack said:


> according to chris. According to me, I know perfectly what an xcross is.
> 
> 
> 
> ...



I need to find a surgeon. My hand seemed to have fused to my face.


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## riffz (Jul 9, 2010)

CharlesOBlack said:


> according to chris. According to me, I know perfectly what an xcross is.



Chris defined it.


B' F' L R2 B2 R' B2 R B' F L R B2 U2 B L B U' R B F2 R' D2 B R'

XCROSS：R' F2 B' D2 R U' L2 B'

So according to you the first xcross you posted is actually not an xcross, seeing as a 2x2x2 is solved before the placement of the last 2 cross pieces. See how stupid and useless your definition is?


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## James Ludlow (Jul 9, 2010)

So was I right?


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## cmhardw (Jul 9, 2010)

Feryll said:


> cmhardw said:
> 
> 
> > I consider Xcross to be either:
> ...



Feryll already posted what I feel counts as all types of what makes an X-cross. I personally would call a 2x2x2 start, with no pre-planning on the other pieces, to be a Petrich solve. Petrich is a very old term for Petrus-turned-Fridrich.

I would argue that if you plan only the 2x2x2 during inspection, but during the solve discover a nice continuation to make it become an X-cross, that it should probably still count as an Xcross. If you plan only the 2x2x2 during inspection, and then place the other cross edges one at a time, it's probably a Petrich solve. Either way, though, this is an incredibly gray area and depends on the person, and how they want to define X-cross.

Whether a solve is termed a Petrich or Xcross solve is not necessarily an important distinction though, the point is that you are utilizing block building to make an easier F2L than a standard cross + 4 pairs approach. So either way it is a good strategy, and can be worth a second or two saved, but the terminology I think is not necessarily as important.

My $0.02,
Chris


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## iasimp1997 (Jul 9, 2010)

CharlesOBlack said:


> not necessarily. *If the 2x2x2 is extended to a 2x2x3 then it isn't an Xcross anymore*.
> 
> Also, I think that a 2x2x2 is a bit different than a cross with a pair inserted. But that's just me.



Technically, it's a double x-cross.


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## CharlesOBlack (Jul 9, 2010)

cmhardw said:


> Feryll said:
> 
> 
> > cmhardw said:
> ...



incredible how I was trying to say that and everybody ignored me, while when YOU said it, everybody shut up.


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## cmhardw (Jul 10, 2010)

CharlesOBlack said:


> incredible how I was trying to say that and everybody ignored me, while when YOU said it, everybody shut up.



I do agree with what you're saying for the most part, but I disagree with the following statement a bit, personally.



> If you made a 2x2x2 and then you added the rest of the cross, it'd be a Petrus-turned fridrich solve though, no matter what (according to my view)



Again, this falls into that gray area I mentioned in a previous post, but I don't always consider a 2x2x2 start to be Petrich. The times I *don't* consider it to be Petrich are:



> 3) seeing the solve for the 2x2x2 during inspection while making sure that the solution for the 2x2x2 puts the other 2 cross edges in a "good" position. A good position means easy to solve in relatively few moves.



For these cases I would argue that your 2x2x2 solution is tailored to influence *both* of the remaining cross edges in such a way as to allow you to solve them in an easy 3-4 moves, or even less hopefully. This is still technically a Petrich start to your solve, but since the 2x2x2 solution was altered/tailored to account for the other cross edges I call it Xcross.

Again, I don't think there is one simple easy definition of what makes an Xcross during a solve. Basically I don't think this question has one solid correct answer. Part of it is this gray area of Petrich/Xcross and how the individual defines it, and I think that's fine.

Chris


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## Kirjava (Jul 10, 2010)

CharlesOBlack said:


> incredible how I was trying to say that and everybody ignored me, while when YOU said it, everybody shut up.




I'm getting bored of arguing about semantics with you, but you seem to have not noticed that a Petrich solve is a certain type of xcross.

My statement is still correct.


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## QCcuber4 (Jul 10, 2010)

i like it, i think ill practice that, it could actually save me what i need in time to reach sub 15 avg. thank you for the examples.


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## uberCuber (Jul 10, 2010)

CharlesOBlack said:


> according to chris. According to me, I know perfectly what an xcross is.
> 
> 
> 
> ...



this whole argument is the most :fp-worthy thing i have seen in a really long time

2x2x2 does not always imply Petrus
thats all there is to it.


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## QCcuber4 (Jul 11, 2010)

uberCuber said:


> CharlesOBlack said:
> 
> 
> > according to chris. According to me, I know perfectly what an xcross is.
> ...



It's not a fail convo, they are discussing about facts and I learned much from reading their posts.


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## Ranzha (Jul 11, 2010)

CharlesOBlack said:


> Ranzha V. Emodrach said:
> 
> 
> > First scramble:
> ...



2x2x3*. Double x-crosses ftw.
I just rescrambled right now to see where that pair was formed, and it was formed in the scramble! I got lucky. :3


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## rubiknewbie (Jul 12, 2010)

X-crosses are awesome! The only problem is I can't do it :fp.


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## yangzhengbao (Jul 14, 2010)

If you do it day by day ,then you can do it.


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## Ranzha (Jul 15, 2010)

X-crosses aren't too hard.
Only go for an x-cross if you know that you can preserve a first-layer corner. plan the cross and find the edge.
During the cross solve, place the edge while the first layer is not ADF'd.
Then, finish cross and ADF.
BAM.
X-cross.
Making a video.


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