Date: Sat, 22 Jun 96 21:58:06 +1000
~~~ ~~~ From: Peter Foster <pfoster@pcug.org.au >
~~~ Subject: Thistlethwaites algorithm (and others)

Morwen Thistlethwaite devised a solution for Rubik's cube which required at
most 50
turns. I would like to know where I can get a copy of this solution. Can
anyone help?
Thistlethwaite's
solution, but that it has been significantly improved and he does not know
the details.
So, if someone can point me in the right direction I would be most grateful!

While I am interested in Thistlethwaite's solution, it is no use for speed
solving.
There was a recent posting, from Jiri Fridrich, which outlined his speed
solution, as
follows:

1. Do the four edges (white first) (2 sec.)
2. Put the white corner including the corresponding edge from the second
slice. When you put all four white corners, two slices on the cube will be
done. In this stage, almost no algorithms are necessary. Most positions
can be solved with intuition. (4 x 2 sec = 8 sec.)
3. Turn all 8 small cubes from the last slice so that the last face has
the same color. There are only 40 different positions (not counting
symmetrical positions). On average, 10 moves are necessary to do this
phase.(3 sec.).
4. Move the cubes in the last slice so that the cube is solved. There are
only 13 different positions. On average, 10-15 moves are necessary. (4
sec.)

For the whole system, 40+13=53 algorithms are necessary. One also needs
about 8 short algorithms for the second phase. Altogether, 61 algorithms
will enable you to solve the cube in 17 seconds on average, if you can
turn 4 turns per second, and if you can minimize time gaps between
algorithms.

Is there any chance of Jiri Fridrich posting these algorithms (or perhaps making
them available via FTP)?

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