- View SourceOver the past few years, I have been exploring new ways of solving the

cube. I pretty much stopped speed cubing during this period, and just

continued experimenting until I found a system I was willing to commit

to. This is not it, but Ron suggested that I describe it to you all

anyway. I have a habit of only revealing the systems that I have no

intention of using (for instance, "tripod"). After all, I don't want to

give my competitors the advantage :-)

As I said, this system requires no thinking. All solutions to all cases

can be memorised and applied, with an end result of maybe 13 seconds

average. Maybe someone is interested in doing that. Personally, I find

it hard to call that puzzle solving - it's more like running the 100

metres.

(btw, I am not competing in this year's championships so people have

suggested that I reveal the system I actually use- I agree. Stay tuned.)

----- Forwarded message from Ryan Heise <rheise@...> -----

From: Ryan Heise <rheise@...>

Date: Sun, 22 Jun 2003 11:30:52 +1000

To: Ron van Bruchem <rvb@...>

Subject: Thistlethwaite, human version

On Sat, Jun 21, 2003 at 06:13:28PM +0200, Ron van Bruchem wrote:

> Hi Ryan,

>

> I am very interested in the ideas you have.

> Please tell me something about the systems you came up with, and how many

> algorithms you need per stage.

Phase 1 -> <U,D,L,R,F2,B2> group

- simple, no algorithms

Phase 2 -> <U,D,L2,R2,F2,B2> group

- Direct up/down edges to up/down face (simple, no algs)

- Direct corners to up/down face (between 8 and 60 algs)

Phase 3 -> <U2,D2,L2,R2,F2,B2> group

- Corners (between 1 and 2 algs)

- Edges (between 1 and 4 algs)

Phase 4 -> place pieces

- Corners (intuitive)

- Edges (intuitive)

DETAILS OF STEPS

* PHASE 1

This is solved in 4.6 moves on average.

* PHASE 2 EDGES

This is rather simple. You can learn all 20-30 cases if you wish. I

forget the exact number. This can be solved in an average of 4 moves.

* PHASE 2 CORNERS

I used a method similar to Gaetan - first get 3 corners oriented on one

side, and then apply one of 8 algorithms. It is possible to directly

learn all 60 cases if you want (I can't remember the exact number).

I think they have an average of 8.5 moves.

* PHASE 3 CORNERS

In phase 3, it is important to do the corners first, because it is

difficult to see whether they have made it into the U2D2L2R2F2B2 group.

Just getting opposite colours on each side isn't enough. The algorithms

you learn to fix this are shorter when you don't have to worry about the

edges.

Here, I'll just describe the simplest technique that requires two

algorithms, but is very quick for the fingers and brain:

First, separate up/down colours (one colour on each side). Average 3.2

moves. There should be, for example, all red corners on top, and all

orange corners on bottom.

Now, pairs of adjacent corners will either match or mismatch. Our goal

is to make them either all match, or all mismatch. So, in this step, we

find the odd pairs out (whether they're matching or mismatching), and

fix them so they match/mismatch like all the rest. There are 4 pairs.

Either one pair is the odd one out, or two pairs are the odd ones out.

For one pair: hold the pair at UF, and do R'FR'B2RF'R. It's a

modification of the corner mover that doesn't care about the exact

positions of corners.

Two pairs: hold two pairs on F (you may need to move them there), and do

R2UF2U2R2U. (if you needed to move them there first, there's also a

trick to get it to work...)

I looked for a long time to find other methods here that used fewer

moves. I found some, but this way was definitely by far the quickest to

perform.

PHASE 3 EDGES

4 cases - simple (2,4,6 or 8 bad edges). Average 6.1 moves.

Total moves so far: 33.4. Obviously, fewer moves are necessary to

achieve an average of 40 moves overall. I worked out some shortcuts, but

I don't think they're worth it, because I could perform the longer way

faster.

PHASE 4 (the end game)

I think you already have a strategy for this. Corners, then edges. I

think it's possible to learn all cases for the edges (about 150 I think,

but easy to memorise).

A downside is the number of double turns which are more difficult to

perform. But I tried a few algorithms and they are possible to do

quickly enough. I think the main benefit of this method is fast reaction

time and no thinking. Another benefit is that it looks cool when you

solve it. None of the pieces are placed until the very end.

Above, I listed each individual step with no shortcuts. It is possible

to combine steps, or do steps in different orders depending on

opportunities. The basic method above, if you learnt all cases for each

exact step, should give an average of 45.7 moves.

Ryan

----- End forwarded message -----

Just a note I'd like to add: it is not necessary to stick to only moves

within each group. For example, in phase 4, it is not necessary to stick

to double turns. In fact, the shortest solutions for most cases involve

single turns. The first half (phases 1-2) already has a lot of freedom

of movement. I suppose it could be solved in 5 to 6 seconds. Maybe

someone has a better way to finish phases 3-4? For example, one idea is

to first get all red on top, and all orange on bottom, then permute.

Another idea is to build up blocks like Fridrich and Petrus (more

intuitive).

Ryan