direct solving the x-cross (a message from chris hardwick)

View previous topic View next topic Go down

direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Tue Sep 02, 2008 10:22 am

obviously..i really like the concept of the extended cross..bago pa lang ako dito sa forum..nagsimula na ko ng threads about xcross...Smile

recently..i read about direct x-cross solving from chris hardwicks site..but i had no idea how to do it..so i emailed him..and this is his reply :

Hi Jolo,

The way I got more comfortable direct solving the extended cross was to do lots of practice solves without timing myself. Sometimes I would take even as much as 10 minutes trying to figure out an Xcross solution for a certain scramble. Keep in mind that when solving only 1 color cross all the time, you should hope to be able to see an X-cross solution about 25% of the time. If you solve 2 different cross colors (opposite colors like I describe here http://www.speedcubing.com/chris/ec-oc.html) then you can expect to use an extended cross approach nearly 50% of the time, which is what I do.

As for how to direct solve I try to make sure that each move I do builds some part of a block, or sets up building a larger block. I might build a 1x1x2 block with the first move out of a corner and an edge. Then I might do 1-2 moves trying to setup turning that block into a 2x2x1 block out of 1 corner and 2 edges. After that I try to put that block together with the 3 remaining cross pieces (the 2x2x1 block is part of the 2x2x2) and see if I can put them all together. Sometimes it it easier to start with the 3 cross pieces and then finish by building and placing the 2x2x1 block.

The best advice I can offer really is to practice on scrambles a lot, and do not time yourself. Over time you'll develop strategies you like and ways you prefer to see how to build the extended cross. I typically view it as 3 cross pieces (edges), and a 2x2x1 block next to one of the cross pieces. Sometimes though I build a whole 2x2x2 block and place the remaining 2 cross edges after that. And even other times I build the whole cross while preserving a corner edge pair, and insert that pair with the last move of the cross, or even after building it.

I know people don't like to hear it, but the best way to get comfortable with extended cross is just to practice, practice, practice.

Hope this helps, and glad to try to put more into words what I do. I think extended cross solving is very good, but don't try to use it all the time. Only use it when you feel you can see nearly the entire solution to it during the pre-inspection. If you can't see nearly the entire solution, it's usually better to just solve the cross alone, then do corner/edge pairs after.

Chris


ayun..i just wanted to share this to you guys..

and of course..thanks to chris hardwick..Smile

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by Guest on Tue Sep 02, 2008 2:30 pm

nice one!
try ko yan...
recently lang ako naging one color..
baka magawa ko pa din ang 2color..
hehehe...

btw, ndi pala suplado si chris.. hehe

thanks jolo for sharing...
malaking tulong yan...

Guest
Guest


Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Tue Sep 02, 2008 5:51 pm

yup..tingin ko magandang combo talaga ang xcross + color neutrality..hoy mitch mag x cross ka na..haha..kasi opposite color solving : 50% x cross..pano pa pag fully color neutral? lagpas 100 %..Razz

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by bonoan1027 on Tue Sep 02, 2008 5:54 pm

jolo_mat2008 wrote:
Hope this helps, and glad to try to put more into words what I do. I think extended cross solving is very good, but don't try to use it all the time. Only use it when you feel you can see nearly the entire solution to it during the pre-inspection. If you can't see nearly the entire solution, it's usually better to just solve the cross alone, then do corner/edge pairs after.

This is very important. Don't force an xCross... Do only when it is simple enough for you.

bonoan1027
3x3x3
3x3x3

Male
Number of posts : 566
Age : 23
Location : Katips
Registration date : 2008-03-21

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by Guest on Tue Sep 02, 2008 8:36 pm

jolo_mat2008 wrote:yup..tingin ko magandang combo talaga ang xcross + color neutrality..hoy mitch mag x cross ka na..haha..kasi opposite color solving : 50% x cross..pano pa pag fully color neutral? lagpas 100 %..Razz

akala ko din dati, d best ka kapag color neutral ka...
pero mas mahirap f2l kapag neutral e..
super bilis naman sa cross..

pero kapag one color,
medyo bumagal sa cross,
pero bumilis naman sa f2l...
e mas matagal pa naman gawin ang f2l...

kaya lang ako naka abot ng sub 30 e dahil nagshift ako sa one color...

pero inabot ako ng 1 week para masanay sa one color..
nanibago kasi sa cross.. hehe

Guest
Guest


Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by marc_rendl on Tue Sep 02, 2008 9:09 pm

wow.. minsan lang ako makakita ng gantong mga sensible posts... nice jolo... ü tagal ko nang di nagcucube kasi busy sa mga exams.. hehe

_________________
LET:
>>cxcxc be a Rubik's Cube
>>U be the set of all tangible Rubik's Cubes,
>>i.e., U={cxcxc | c is an integer and lies in the interval [2,11]}
>>C be the set of my cubes on hand
>>S={2, 3, 4, 5}
MY CUBES ON HAND CAN BE THE DESCRIBED BY THE SET C where...
>>C={nxnxn element of set U | n is an element of S}


UPD. MATH MAJOR. PERIOD.

marc_rendl
2x2x2
2x2x2

Male
Number of posts : 397
Age : 27
Registration date : 2007-10-24

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Tue Sep 02, 2008 9:14 pm

hehe tnx kuya marc..napansin ko rin un..Razz ahh..kaya pala walang up cubemeets these days..exams nyo..kakatapos lang din ng math11 dep exam namin eh..haha..sayang tinotopak pa naman mga prof ko sa archi..madalas maaga mag dismiss:P

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by ynajatrice on Fri Sep 12, 2008 8:59 pm

oi jolo, paturo ng x-cross

at pati sa mga color neutral

i need that

hahaha

anyway, x-cross really saves time

at nakakatuwa dahil nag-reply si chris

hehehe

nice post! (i agree with marc)

Smile

_________________
an algorithm a day keeps those bad times away...
***avatar: mit meine Tochter(mein Haar ist hässlich , hahaha)***
Ich heiße JUMEL ^^,
Let ε < 0
HAHAHA

ynajatrice
2x2x2
2x2x2

Male
Number of posts : 456
Age : 27
Location : Fairview, QC
Registration date : 2007-08-14

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Fri Sep 12, 2008 9:46 pm

@ kuya jumel : haha hindi ako masyadong magaling..nageexcross lang talaga ako kapag may easy case..pero tingin ko bagay nga talaga sa color neutral ang x-cross..Razz cge turo ko sayo ung naintindihan ko sa site ni chris hardwick pag may up meet..hehehe..Smile

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by oretniprac on Fri Sep 12, 2008 9:47 pm

jolo_mat2008 wrote:yup..tingin ko magandang combo talaga ang xcross + color neutrality..

Color neutral din ako, simula palang ako nagcube CN nako hehe(di ko nga alam na may ganun pala noon) . Ang prob. ko pag gumagawa ko ng xcross yung time ko eh halos pareho lang sa pagsolve ko ng normal, di ko naman fnforce pag gawa ng xcross, pag may nakita talaga akong madali gawin ginagawa ko na. Kailangang-kailangan ko talaga yang xcross! hahaha para kahit papano maka sub20 naman ako harhar. yun yung advantage ng pagiging color neutral


@ynajatrice
diba color neutral din kayu? hehe. Mabuhay ang mga Color Neutral!!

oretniprac
3x3x3
3x3x3

Male
Number of posts : 569
Age : 26
Location : Las Pinas :D
Registration date : 2008-03-30

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Fri Sep 12, 2008 9:48 pm

@ carpi : baka sa execution..Very Happy baka mabagal lang ang execution o kaya naman masyadong maraming moves..hehehe.Very Happy

kala ko mababaon na talaga to sa limot eh..Smile)

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by lorcan on Fri Sep 12, 2008 9:57 pm

@jolo_mat2008

kuya malabo n mwla ata to eh =)

lorcan
2x2x2
2x2x2

Male
Number of posts : 279
Age : 25
Registration date : 2008-01-28

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jusay_mitch29 on Sat Sep 13, 2008 10:31 am

lols nabuhay na naman ung xceoss topic... hehehe madami na siguro gumagamit nito

jusay_mitch29
4x4x4
4x4x4

Number of posts : 1245
Age : 23
Registration date : 2008-01-28

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by bonoan1027 on Sat Sep 13, 2008 10:48 am

Oh yeah... many people... when they do the xCross.. they look at their every move and look for the 1st pair after the xCross.

In my opinion.. this is somewhat like "forcing it" because you need to make sure it will be correct by putting your attention to it...

Like what sina kuya Jonathan said... Try doing the cross blindfolded.. The same goes for extended cross. It should be learned how to be done without noticing the xCross pieces.

In Chris Hardwick's site... the average moves of his xCross examples are 10-13.

If I were to choose to do a 10-13 move xCross... I think it will be okay despite the ideal cross move count is 7 as long as the transition between that xCross and the 2nd F2L pair will be as fast.

But for me... I'd only go for xCrosses that go for around 7 moves since it's easier to execute without looking at it and also since 10-13 move xCrosses are just like having to do a cross and find the 1st F2L pair... Afterall... xCross is supposed to be for the optimization of your cross. Even during FMC.. xCross may just be taking more moves than the normal cross and 1st F2L pair. Just saying.

Smile THE END

bonoan1027
3x3x3
3x3x3

Male
Number of posts : 566
Age : 23
Location : Katips
Registration date : 2008-03-21

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jestoni143 on Sat Sep 13, 2008 11:52 am

bonoan, xcross at 7 moves need pure luck, especially if you are color neutral. say you are a white biased cuber, and you found your scramble to have more than 9 moves to do xcross,and, at the same time, you found c/e that do not have adjacent colors to white, but would have 7 move xcross; would you rather go for normal cross or proceed to the 7 move cross with no-white xcross?

most often, 7-9 moves ang optimized xcross, lalo na pag di ka color neutral... pang fmc lang talaga dapat ang xcross, but to petrus users, madali na maka 7-9 move xcross, that is, if you won't proceed to 2x2x3 and opt for the xcross instead.

_________________
Use Petrus and get it fast!

jestoni143
2x2x2
2x2x2

Male
Number of posts : 132
Age : 29
Registration date : 2007-06-29

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jhameel_killua03 on Sat Sep 13, 2008 12:24 pm

thanks for sharing kuya jolo...

jhameel_killua03
2x2x2
2x2x2

Male
Number of posts : 385
Age : 22
Location : Paco, Manila
Registration date : 2008-04-03

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by bonoan1027 on Sat Sep 13, 2008 12:32 pm

@jestoni143

It doesn't have to be pure luck... here... I'll post 3 random scrambles then show my xCross solution and my cross solution... just to show... there's (most of the time) a way

1. U' B' D2 L2 U L2 U2 R2 D2 U R2 B2 R F B2 U R U' F2 D F U2 F2 U L2

xCross: F2 R' U R' L' B L D ( 8 )
Cross: F2 R U' R B' D (6)

2. F R' L2 B2 L' B F2 R' D' L2 R' D' R' B F L F' D U B' R' L U L F2

xCross: y' R D' L B2 D' R2 D R ( 8 )
Cross: y' L D' R' D U' F2 (6)

3. D U' R2 B F R2 D R2 L' F U2 R F U D' B' D' F' L' F2 R B R2 B F'

xCross: y2 E' L' F' R F2 R' D F2 ( 8 )
Cross: y U F R' L D L' (6)

this is what I mean by optimization of the xCross... the normal number of moves done in a normal cross should have the minimal difference with the number of moves for the xCross

From my point of view (white biased), I don't want to bother myself with long xCrosses... Also with easy xCrosses yet different starting colors... even Harris Chan and Nakajima don't bother themselves with it (and they only start with 1 color )... kasi they have good cross-f2l transition.

bonoan1027
3x3x3
3x3x3

Male
Number of posts : 566
Age : 23
Location : Katips
Registration date : 2008-03-21

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jestoni143 on Sat Sep 13, 2008 12:43 pm

what you posted previously, you'd rather go for a 7-move-cross, it's almost pure luck!

and you posted above 8-move cross... but anyway, i agree with you that you should not bother yourself to a 9 move xcross... just proceed to normal cross instead...

_________________
Use Petrus and get it fast!

jestoni143
2x2x2
2x2x2

Male
Number of posts : 132
Age : 29
Registration date : 2007-06-29

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jolo_mat2008 on Sat Sep 13, 2008 1:00 pm

i tried enzo's scrambles without peeking at his xcross solutions :

scramble 1 : 17.74
scramble 2 : 24.34
scramble 3 : 18.45

so..yeah..obviously mas mabilis ang times ko kapag may x cross..sa second scramble..forced x cross na yan..hehe..i ran out of time (naubos ung 15s inspection time ko) to plan the x cross..kaya ayun..hehe sira ung solve..anyway..madali lang naman talaga mag xcross..BUT you need to know when an x cross is worth doing and when it's not.Smile

_________________

mailap ang sub20
DID SOMETHING WRONG OR BAD?
no time to cube. it's major plate season.
my quest for a sub20 average will start as the sembreak starts


jolo_mat2008
3x3x3
3x3x3

Male
Number of posts : 996
Age : 24
Location : QC (i live in sm north edsa..:P)
Registration date : 2008-03-18

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by oretniprac on Sat Sep 13, 2008 1:20 pm

Nag-ppractice ako ng xcross, yung mga scramble galing sa Rubik's Jtimer, ok naman lahat, nag-sslow solve pero di ako nag ttime hehehe, tapos biglang lumabas tong scramble:

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

nakagawa ko double xcross boom! wapak

y' x' L R' D2 B L R2 = 6 moves lang sya pero yung cube rotation sa umpisa nakakalito

super lucky talaga, kasi isa lang yung nakita ko xcross pero nung nag R2 na ko(yung last move) nagulat ako may isa pang pair na na-solve na, kaya ayown, try nyu rin hehehe...

EDIT: ayun, tinry ko i-time 11.22 secs, try nyu rin baka mag sub10 pa kayo dyan haha

oretniprac
3x3x3
3x3x3

Male
Number of posts : 569
Age : 26
Location : Las Pinas :D
Registration date : 2008-03-30

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jusay_mitch29 on Sat Sep 13, 2008 6:15 pm

basta ito pag sanay ka na mag xcross kahit 9 moves pa yahn it wouldn't hurt your time... f2l ang kelangan mo pagtuusan...

jusay_mitch29
4x4x4
4x4x4

Number of posts : 1245
Age : 23
Registration date : 2008-01-28

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by ynajatrice on Sat Sep 13, 2008 6:29 pm

oretniprac wrote:
jolo_mat2008 wrote:yup..tingin ko magandang combo talaga ang xcross + color neutrality..

Color neutral din ako, simula palang ako nagcube CN nako hehe(di ko nga alam na may ganun pala noon) . Ang prob. ko pag gumagawa ko ng xcross yung time ko eh halos pareho lang sa pagsolve ko ng normal, di ko naman fnforce pag gawa ng xcross, pag may nakita talaga akong madali gawin ginagawa ko na. Kailangang-kailangan ko talaga yang xcross! hahaha para kahit papano maka sub20 naman ako harhar. yun yung advantage ng pagiging color neutral


@ynajatrice
diba color neutral din kayu? hehe. Mabuhay ang mga Color Neutral!!

mabuhay tayo! hahaha!

hindi na ako nagcucube masyado

i'm stuck at 25 for the past 4 months!!!

pag sem break, mag-aaral na ako

sa lahat ng color neutral jan

share your thoughts naman

kasi ako, wala pa

hahaha

Smile

_________________
an algorithm a day keeps those bad times away...
***avatar: mit meine Tochter(mein Haar ist hässlich , hahaha)***
Ich heiße JUMEL ^^,
Let ε < 0
HAHAHA

ynajatrice
2x2x2
2x2x2

Male
Number of posts : 456
Age : 27
Location : Fairview, QC
Registration date : 2007-08-14

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by jusay_mitch29 on Sat Sep 13, 2008 6:45 pm

wahahaha ako lahn ata color neutral na xcross user na sub 20 na... kaya nio yahn mga kauri

jusay_mitch29
4x4x4
4x4x4

Number of posts : 1245
Age : 23
Registration date : 2008-01-28

View user profile

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by Jome on Sat Sep 27, 2008 3:31 pm

Parang ang tagal na nito ah. Hanggang ngayon xCross pa rin ang usapan. And yes, maganda ang method ni Chris Hardwick. That is why that's what I used nung active cuber pa ako, which I also taught some people how to do. Obviously, di natatandaan. Haha.

Cheers sa lahat ng sensible magpost. Ang tagal na rin since ng last sensible post na nakita ko dito.

_________________
3x3x3 SS: 12.79s, 12.12 (PLL skip)
3x3x3 PB ave.: of 10, 18.37s; of 5, 17.62s
Official WCA Record

Will kill spammers for free.
No, my pic is not edited. I've got red eyes! Beware, spammers!

Jome
2x2x2
2x2x2

Male
Number of posts : 398
Age : 28
Location : Malate, Manila
Registration date : 2007-11-25

View user profile http://scarredpetal.livejournal.com

Back to top Go down

Re: direct solving the x-cross (a message from chris hardwick)

Post by Sponsored content Today at 1:24 am


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum