- Sep 5, 2003What a very detailed reply Ryan!

Here's where I'm up to at the moment... I've learnt several LL edge

algs -- ones that mess with the corners (which doesn't matter if LL

edges are oriented first). I already knew several LL edge algs that

preserve the corners -- I guess these are useful if the corners are

already done when you get to the LL.

I already know the Sune and its mirror (can't imagine there'd be any

cuber who doesn't know this alg?!). I've learnt the algs for the

three LL corner orientation positions where 2 are corrent and 2

require twisting. Still need to learn the 2 algs for when all 4

require twisting.

I'm aiming to learn the 13 PLL if my enthusiasm lasts that long. In

case it doesn't, I planned the order that I would learn the algs.

First I revised the algs that just move the edges since. I knew U and

H, but for some reason was a bit iffy with Z. After that, I just

ranked them by 'probability of occurrence'. So, of the remaining 10,

I've memorised the algs with a frequency of 1/9 or greater (A, R, J,

G). So, 7 down, 6 more to go.

I think I need to take a break from new algs and spend some time

getting the newly memorised algs firmly planted in my head. I'm

finding that I can remember them without a problem, but I'm still

taking a bit of time recognising the patterns. I'm not concerned

though because I know that practise will fix this!

Jasmine.

--- In speedsolvingrubikscube@yahoogroups.com, Ryan Heise

<rheise@p...> wrote:> On Mon, Sep 01, 2003 at 11:48:01AM -0000, jasmine_ellen wrote:

a

> > I remembered that DanK had something like this on his site about

> > beginner method, an intermediate method and an advanced method.

This

> > is actually what I was after. Who else has something like this on

used.

> > their site?

>

> I'll describe the beginner and intermediate methods that I once

> They are simplications of the Fridrich last layer system. You need

to

> first understand how that system works:

because

>

> http://www.ws.binghamton.edu/fridrich/system.html#last

>

> This general strategy, orienting first, then permuting, is good

> it is very easy to recognise the positions quickly. But instead of

and

> orienting all the pieces at once, you just orient the edges first,

> the corners second.

patterns,

>

> BEGINNER METHOD

>

> First, orient the 4 edges (ie. make a cross). There are only 4

> and one algorithm to solve them all! To view this, you need to use a

take you

> fixed width font:

>

> --- --- -x- -x-

> -x- xxx xx- xxx

> --- --- --- -x-

>

> For each pattern, apply the algorithm "R'U'F'U F R" and it will

> to the next pattern. Eventually you will end up with a cross.

applying the

>

> Improvement: notice that if you apply the algorithm when you already

> have the cross, you will end up with a line. That means that you can

> jump immediately from the 2nd pattern to the 4th pattern by

> algorithm backwards! So, this step should take an average of 6

moves.

>

solved.

> Next, orient the corners. There are only 6 patterns apart from

> Look through this complete list, and find all the patterns (and

Sune TM

> algorithms) that have a cross already formed:

>

> http://www.ws.binghamton.edu/fridrich/Mike/orient.html

>

> For the case when 3 corners need to be twisted, I recommend the

> algorithm from Petrus. See the applet at the top/right of his page:

bottom

>

> http://lar5.com/cube/fas6.html

>

> I think it's useful to learn to twist them forwards and backwards:

>

> - R U R'U R U2 R'

> - R'U'R U'R'U2 R

>

> To see that done fast, have a look at the quicktime movies at the

> of this page:

cases

>

> http://lar5.com/cube/speed.html

>

> I recommend this algorithm because one of the other orientation

> can be solved by just applying this algorithm twice. To know which

case

> I'm talking about, apply this to a solved cube: RU2R'U'RUR'U'RU'R'.

do:

>

> Now, apply the sune (RUR'URU2R') twice:

>

> RUR'URU2R' + RUR'URU2R'

>

> Notice that the moves in the middle cancel out? So you can actually

>

sides of

> RUR'URU'R'URU2R'

>

> which is an "optimal" solution.

>

> Next, permute the corners (yes, before the edges). Most of the time

> there will be a 3 cycle of corners. In this case, look at the 4

> the last layer. On one of the sides, the two last layer corners

will be

> matching in colour. Hold those two corners on the back side and do:

that

>

> R'FR' B2 RF'R' B2 R2

>

> Now the corners should be solved. If you don't find any two corners

> match, apply the above algorithm and that should result in a

position

> where two corners match. Don't worry, this case rarely happens. If

you

> want, you can learn a special algorithm for that case by picking the

an

> most attractive one from:

>

> http://www.ws.binghamton.edu/fridrich/Mike/permute.html

>

> The "Y" pattern on that page has the desired corner effect.

>

> Next, permute the edges. Again, most of the time, there will be a 3

> cycle of edges. You need to learn to cycle the edges forwards and

> backwards:

>

> - R2U FB'R2F'BU R2

> - R2U'FB'R2F'BU'R2

>

> Sometimes, all 4 edges need to be swapped in opposite pairs. That's

> easy case, so why not learn it:

learning.

>

> RLU2R'L' [U] R'L'U2RL

>

> The [U] means rotate the whole cube from the up side, 90 degrees.

>

> There's also a rare case where all 4 edges need to be swapped in

> adjacent pairs. The algorithm's difficult so it's not worth

>

to

> INTERMEDIATE METHOD

>

> First, orient everything like the beginner method. Then permute

> everything like the full blown Fridrich method.

>

> How can you learn all the permutations? See my previous email:

>

> c

>

> There, I list which algorithms to learn first, and which algorithms

> learn last.

last

>

> ADVANCED METHOD

>

> You already know enough! It is not necessary to learn 40 orientation

> algorithms. 6 is enough. Gilles Roux proved that it is possible to

> achieve sub-20 times with just these 6 orientation algorithms and 13

> permutation algorithms. He used the petrus method for the first two

> layers which gives you a cross automatically when you get to the

> layer. Using that strategy, those extra orientation algorithms are

not

> needed.

>

> Ryan - << Previous post in topic Next post in topic >>