# Request for Big cubes Edges scrambler



## Akash Rupela (Dec 18, 2011)

For being good on big cubes, its necessary to be good on all 3 parts of your solve( edges, centers and 3x3) . The centers can be practiced on normal scrambles, and 3x3 can be practiced by applying a 3x3 scramble to a bigger cube. But its really a problem that there is no edges scrambler which keeps the centers solved but mixes up the edges.

Thus its difficult to practice the edges alone (without solving centers again and again) and that is why a large majority of cubers suck at edge pairing. True, with practice anything can be done, but I really believe , an edge only scrambler for big cubes will be a great help in improving our times on big cubes.( by edge only, i dont mind if it scrambles corners or anything else too, just no inner pieces)

Thank you
(i couldnt find any such post, if there was one already, i apologise)


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## Kirjava (Dec 18, 2011)

Akash Rupela said:


> that is why a large majority of cubers suck at edge pairing.


 
no, it's because edge pairing is hard


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## MostEd (Dec 18, 2011)

Akash Rupela said:


> Thus its difficult to practice the edges alone (*without solving centers again and again*)


 
Didn't you say you practice centers? There's more for ya.


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## qqwref (Dec 18, 2011)

Okay, but how do you propose actually creating such a scrambler, without having it use a huge number of moves?


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## HelpCube (Dec 18, 2011)

qqwref said:


> Okay, but how do you propose actually creating such a scrambler, without having it use a huge number of moves?


 
He doesn't, he's asking somebody else to make one. That's why it says request. I don't see how it would take a huge amount of moves though, explain?


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## Escher (Dec 18, 2011)

It would be easy to make a crap one. Using strings that damage the centres, do a face move, and then restore them, and rotations, you could affect 'edges only'. 

Example: r U r' U r U2 r' (U' F') l' U' l U' l' U2 l

The thing is you would have to repeat that and variations a huge number of times. Probably more moves than just scrambling + solving centres.


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## wontolla (Dec 18, 2011)

Look at AvGalen's edge pairing examples. The way he scrambles is the same idea as Escher's. Just introduce some changes between those moves every time.

But as the others say, it is probably more fun to do centers instead of following scrambles with 100s of moves.


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## vcuber13 (Dec 18, 2011)

I think it would work better with something like: u d2 R U2 R' y d R' D' R u' d


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## qqwref (Dec 18, 2011)

HelpCube said:


> He doesn't, he's asking somebody else to make one.


Yes, and I'm asking the OP (or somebody else) to propose an algorithm so I can make a scrambler out of it. You don't just "make" a scrambler; you need to figure out how you want to create the scrambles first. In this case it's not obvious.



HelpCube said:


> I don't see how it would take a huge amount of moves though, explain?


Suppose we're using a 5x5x5. A method like AvG's is cool but doesn't ensure randomness. You could also generate a random position and solve it, but that would take a lot of moves (probably at least 60ish). Plus there's the question of bigger cubes - you could just do a smaller cube scramble multiple times, but there's probably a better way to do it. Anyway, I'd like for the edge scrambler to not take *more* moves than the full-cube scrambler.


EDIT: New idea:
r l
u' d (R U R') u2 (F' D2 F) d u2 (B U B') d (L U L') u' (L' D2 L)
u2 d U r' l'
The first line is setup and the last is center fixes; the middle part has 5 iterations here but could go as high as we want. Each one is 3-5 moves.


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## Stefan (Dec 18, 2011)

qqwref said:


> You could also generate a random position and solve it, but that would take a lot of moves (probably at least 60ish).


 
If you use your normal method for that, you'll somewhat practice solving while scrambling (not recognition, but turning).


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## Benyó (Dec 18, 2011)

or just practice the the whole solve, it won't hurt at all


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## Lucas Garron (Dec 18, 2011)

qqwref said:


> Okay, but how do you propose actually creating such a scrambler, without having it use a huge number of moves?


Generate a random edge pairing, then use a computer-friendly pairing method to search for a decently short solution.

This sounds like a fun problem to solve directly, but I'd rather focus on other stuff.

At this point, the most feasible thing for 4x4x4 is probably to use Shuang Chen's reduction solver. It should be able to generate scrambles for this faster than it takes for a human to solve them (and an EP randomization phase wouldn't be very long, in case we're worried about a full random wing permutation).


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## qqwref (Dec 19, 2011)

Lucas Garron said:


> At this point, the most feasible thing for 4x4x4 is probably to use Shuang Chen's reduction solver. It should be able to generate scrambles for this *faster than it takes for a human to solve them*


Heh.

I think I'm going to just go with the idea I had a few posts up (modified slightly to allow for parities). It should be in the next version of qqTimer, which will be released very very soon, since it's been too long since the official release has had all the new changes.

EDIT: Here's a sample 6x6x6 edge scramble. Notice the parity stuff at the very end.
3r r 3b b u 3u2 d' L D2 L' u 3u d L' D L u2 d' F U F' u 3u d2 B U' B' u' 3u2 d' F D F' u2 3u' d2 R D' R' u d B U B' u 3u d2 F' D F 3u2 d' U' 3b' b' 3r' U2 r U2 r U2 r U2 r


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## DaKrazedKyubizt (Dec 19, 2011)

why don't you just.... pretend the centers are solved? That'd pretty much do the job, wouldn't it?


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## JonnyWhoopes (Dec 19, 2011)

DaKrazedKyubizt said:


> why don't you just.... pretend the centers are solved? That'd pretty much do the job, wouldn't it?


 
Nope. There'd be no practical way to know if you had intact centers at the end of the "solve".


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