Loading ...
Sorry, an error occurred while loading the content.

6531Re: Working on learning a 3-look LL

Expand Messages
  • d_funny007
    Sep 5, 2003
    • 0 Attachment
      Simple solution to your 4 corners twisted problem: double-sune and
      bruno (R'U2R2UR2UR2U2R'). DanK/Mirek's Z Perm is the way to go, look
      up DanK video on it... so you don't end up getting a bad habit of
      the brute force alg.

      I'm going through the same phase, teaching a friend of mine that's
      at about 50s. (Just last night planning how to line up the next 8
      PLLs: he knew the 3 edge ones, so I gave him the T and Y to start
      off with... A and V might be the next step).

      -Doug


      --- In speedsolvingrubikscube@yahoogroups.com, jasmine_ellen
      <no_reply@y...> wrote:
      > What 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:
      > > > I remembered that DanK had something like this on his site
      about
      > a
      > > > beginner method, an intermediate method and an advanced
      method.
      > This
      > > > is actually what I was after. Who else has something like this
      on
      > > > their site?
      > >
      > > I'll describe the beginner and intermediate methods that I once
      > used.
      > > They are simplications of the Fridrich last layer system. You
      need
      > to
      > > first understand how that system works:
      > >
      > > http://www.ws.binghamton.edu/fridrich/system.html#last
      > >
      > > This general strategy, orienting first, then permuting, is good
      > because
      > > it is very easy to recognise the positions quickly. But instead
      of
      > > orienting all the pieces at once, you just orient the edges
      first,
      > and
      > > the corners second.
      > >
      > > BEGINNER METHOD
      > >
      > > First, orient the 4 edges (ie. make a cross). There are only 4
      > patterns,
      > > and one algorithm to solve them all! To view this, you need to
      use a
      > > 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
      > take you
      > > to the next pattern. Eventually you will end up with a cross.
      > >
      > > 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
      > applying the
      > > algorithm backwards! So, this step should take an average of 6
      > moves.
      > >
      > > Next, orient the corners. There are only 6 patterns apart from
      > solved.
      > > Look through this complete list, and find all the patterns (and
      > > 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
      > Sune TM
      > > algorithm from Petrus. See the applet at the top/right of his
      page:
      > >
      > > 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
      > bottom
      > > of this page:
      > >
      > > http://lar5.com/cube/speed.html
      > >
      > > I recommend this algorithm because one of the other orientation
      > cases
      > > 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'.
      > >
      > > Now, apply the sune (RUR'URU2R') twice:
      > >
      > > RUR'URU2R' + RUR'URU2R'
      > >
      > > Notice that the moves in the middle cancel out? So you can
      actually
      > do:
      > >
      > > 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
      > sides of
      > > 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:
      > >
      > > R'FR' B2 RF'R' B2 R2
      > >
      > > Now the corners should be solved. If you don't find any two
      corners
      > that
      > > 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
      > > 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
      > an
      > > easy case, so why not learn it:
      > >
      > > 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
      > learning.
      > >
      > > 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
      > to
      > > learn 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
      > last
      > > layer. Using that strategy, those extra orientation algorithms
      are
      > not
      > > needed.
      > >
      > > Ryan
    • Show all 11 messages in this topic