WCA Regulations 2008 draft open for public feedback

[Dene]

Ok, and if the 3x3x3 only has to be in a "random" state, why is there an amount of moves that need to be applied to the other varieties of cubes? the 2x2x2, for example, still requires a 25 move scramble. It doesn't make much sense to me, to only apply this rule to the 3x3x3

 

[Hadley4000]

# 12a3) Clockwise, 180 degrees: F2, B2, R2, L2, U2, D2 (see 12a1).
# 12a4) Counter clockwise, 180 degrees: F'2, B'2, R'2, L'2, U'2, D'2

Why is that needed? Doesn't matter which way you go, if it's 180, it's 180.


I'm surprised they didn't wait until they had the blindfold thing worked out before this.

 

[Dene]

They need to set a standard for all notation. For finger-trick friendly algorithms, if you are trying to describe the algorithm perfectly, then you need a standard notation to follow to show the direction of a 180 degree turn.

 

[hait2]

i wub the new multi-blind change for obvious reasons

 

[Lucas Garron]

Ok, and if the 3x3x3 only has to be in a "random" state, why is there an amount of moves that need to be applied to the other varieties of cubes? the 2x2x2, for example, still requires a 25 move scramble. It doesn't make much sense to me, to only apply this rule to the 3x3x3

Okay, you go write an efficient random-state scrambler for 5x5x5. Anyhow, the scramble has a smaller impact on the times of bigger cubes.
However, I did try to propose doing this for 2x2x2, but it wasn't put in the regs.
If Kociemba adds explicit 2x2x2 (i.e. 3x3x3 corner) functionality, I'm sure the WCA will mandate it.
I also already mentioned a lot of things here.

 

[Rune]

I suppose the pseudorandom numbers are formed
in some recursive way. What prevents us from using the quadrate of the most significant bits in two subsequent numbers, in such way getting (e.g.) 32 bits instead of 16?

I am however not sure that Cube Explorer is nearly perfectly random. It's natural for programmers to encode the solved state with the number zero. Now if Cube Explorer generates a number and interprets it as a cube state, and its random number generator uses lets say just 16 bits, then there are at most 65536 numbers it can generate, and the number representing the solved state would (probably, I believe) be among them. In other words, we might have a 1/65536 chance for it to give us the solved state, instead of the desired 1/(4e19).

 

[AvGalen]

Finally, if Cube Explorer is required anyway I would like it if FMC-scrambles would be provided in optimal form

Wouldn't FMC scrambles be the candidate for not being provided in optimal form? What happens if a competitor comes along, and calculates out the optimal path, which just happens to be the reverse of the scramble? Or someone uses the scramble, but inserts an identity or a slight scramble in the middle, and then fixes the slight scramble at the end. Seems like you're giving the competitor the answer and it would be very difficult for a judge to recognize if they're cheating or not.

I have provided optimal scrambles for many weeks and it only has advantages for the competitors. When a judge has doubts about the solution he can ask the competitor to explain it. Also "the solution must not be related to the scramble in any way" is part of the rules.

 

[Hadley4000]

OK. As far as the scrambles go, why did they even feel the need to change it? Wasn't it alright already?

 

[Bryan]

When a judge has doubts about the solution he can ask the competitor to explain it. Also "the solution must not be related to the scramble in any way" is part of the rules.

OK, after seeing someone's solve, there are many people here who can explain what the person is doing, even if they couldn't have figured it out for themselves. I think a competitor might be able to bluff their way past the judge.

But consider this, if a genius was able to calculate the optimal path, then it would be the reverse of the scramble. You've prevented him from acheiving the goal of the event.

 

[AvGalen]

When a judge has doubts about the solution he can ask the competitor to explain it. Also "the solution must not be related to the scramble in any way" is part of the rules.

OK, after seeing someone's solve, there are many people here who can explain what the person is doing, even if they couldn't have figured it out for themselves. I think a competitor might be able to bluff their way past the judge.

But consider this, if a genius was able to calculate the optimal path, then it would be the reverse of the scramble. You've prevented him from acheiving the goal of the event.

No genius has been able to do it so far. Actually, all cubes seem to be solvable in 20 moves or less and the best anyone has done so far is 28. The best anyone has done at home (as far as I know) is 19 on a 17 move optimal scramble. And the provided optimal solution would often not be the only optimal solution. In theory you are right, but practically the benefits of using optimal scrambles are more important for getting good results.

But let's put it to a test:
Optimal alg: F2 R B2 R2 F2 U2 R2 U L2 B' D F2 U' B2 L2 F' L U'
Please explain (bluff) how you found the inverse solution