# WCA Regulations 2008 draft open for public feedback



## Ron (Mar 18, 2008)

WCA Regulations 2008 draft open for public feedback.
http://www.worldcubeassociation.org/forum/viewtopic.php?f=4&t=421


----------



## pjk (Mar 18, 2008)

Great, looks good. I like this:


> 9f16) For the 3x3x3 Cube: Multiple Blindfolded event the order in the results is based on number of puzzles solved minus the number of puzzles not solved (higher is better). If the result is 0 or lower, the solve is disqualified. If competitors have the same result, then the order is based on total time (lower is better).


I have a question about this:


> B2d1) The competitor must remove the cover from the puzzle after starting the timer..


What does this mean?

Also, on a sidenote, is there a limit to the number of competitions that can occur in a location within a given period? If you have a group of 15 guys at a school, what is stopping creating a competition each weekend?


----------



## Harris Chan (Mar 18, 2008)

pjk said:


> Also, on a sidenote, is there a limit to the number of competitions that can occur in a location within a given period? If you have a group of 15 guys at a school, what is stopping creating a competition each weekend?



I heard that there is a 4 competition-per-year-per-state/provinces rule.


----------



## Ron (Mar 18, 2008)

Please post your feedback on the WCA forum, so that everyone can see it.
It is better to keep the discussion centralized.

Thanks,

Ron


----------



## AvGalen (Mar 19, 2008)

I would like to post there Ron, but I cannot register.
On http://www.worldcubeassociation.org...&coppa=0&sid=81dc40bf47eb5e89676afee4218d1db5 I click on the "I agree to these terms" button, but only a screen refresh occurs.

So far the new rules seem to make sense, although 8 minutes per cube for multi-blind seems a bit steep. The Dutch record has been 2/2 in 27:41, 26:20, 19:47 and 18:08. According to H1b1) When the total time is reached, the attempt is stopped and the number of solved and not solved puzzles is counted. That would have meant 1/2 in most cases. According to 9f16) For the 3x3x3 Cube: Multiple Blindfolded event the order in the results is based on number of puzzles solved minus the number of puzzles not solved (higher is better). If the result is 0 or lower, the solve is disqualified.
If competitors have the same result, then the order is based on total time (lower is better). the result would have been 1-1=0 so it would have been disqualified. I think this rule should be changed to "if the result is < 0".
Also, people that don't solve entire cubes at once (like Clément Gallet and me, we orient every cube first) would be at a disadvantage with these rules. I don't think the method of solving should have an impact on the results.

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


----------



## ExoCorsair (Mar 19, 2008)

AvGalen said:


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



I wholeheartedly concur.


----------



## Dene (Mar 19, 2008)

I like the new OH rule, in that observation can be done with both hands, definitely better. I wonder about the 3x3x3 scramble, though. There is no longer a limit to the amount of moves done, as long is it is in a "random position"? I could do U2, R' B L, and it would look moderately "random" to an inexperienced cuber/someone who doesn't cube at all. This is far too general.


----------



## DennisStrehlau (Mar 19, 2008)

8 minutes per cube in multi...10 would be better, but its okay i think...

Greetings...Dennis


----------



## Lucas Garron (Mar 19, 2008)

Dene said:


> I like the new OH rule, in that observation can be done with both hands, definitely better. I wonder about the 3x3x3 scramble, though. There is no longer a limit to the amount of moves done, as long is it is in a "random position"? I could do U2, R' B L, and it would look moderately "random" to an inexperienced cuber/someone who doesn't cube at all. This is far too general.


What? It's been shown that the current scrambling system produces cubes that are not scrambled random enough. Yes, a 4-move scramble could show up, but 1) it's actually less likely now, and 2) the event's judge would probably remove that scramble.
And the directions are now very specific, while previous definitions were vague and general (terms were even used and not defined).
Random-state scrambling is really the est we can do, we just need to handle it appropriately.


----------



## Dene (Mar 19, 2008)

But is "random" not one of those undefined words? The cube in its solved state could be seen as "random".


----------



## tim (Mar 19, 2008)

Dene said:


> But is "random" not one of those undefined words? The cube in its solved state could be seen as "random".



Random means uhm.. random. A scramble wasn't really random. The scramble itself was, but not the cube, which was scrambled with that scramble.


----------



## Bryan (Mar 19, 2008)

Harris Chan said:


> pjk said:
> 
> 
> > Also, on a sidenote, is there a limit to the number of competitions that can occur in a location within a given period? If you have a group of 15 guys at a school, what is stopping creating a competition each weekend?
> ...



Well, all competitions need to have WCA approval, so I'm sure they would just stop approving them. 

Harris, in the WCA forum I asked about this, and Ron's response was basically "If you're going to have many competitions, try to move them around a bit so many people can participate." But he didn't say there was an official limit. I believe you even responded to that post.

As for "random" position, I believe what Cube Explorer does is the equivilant of taking apart the cube, putting it together randomly (and knowing to avoid parity) and then determine the algorithm to get to that position. It's not just "mix it up randomly".


----------



## cmhardw (Mar 19, 2008)

Dene said:


> But is "random" not one of those undefined words? The cube in its solved state could be seen as "random".



True, but we're assuming that Cube Explorer operates on close to a uniform distribution when producing all of the possible states.

So yes, the solved state is a random state. This makes perfect sense.

However, the probability (we hope) of Cube Explorer producing the solved state is 1/43252003274489856000

So I don't see the problem?

Chris


----------



## AvGalen (Mar 19, 2008)

The solved state is indeed one of those random states. And if it would ever be the official "scramble" I will allow it (after checking with the WCA-delegate). However, you should really think about the chances that this would happen. Please read http://kociemba.org/performance.htm for details, but to summarize:



> moves Probability
> 0 2.31203 *10-20
> 1 4.16166*10-19
> 2 5.61824*10-18
> ...


 
Basically that means you will almost always get a scramble that will require between 16 and 19 moves
Getting a complete last layer skip > 1000's times more likely to happen compared to getting a <= 11 moves scramble.
And if you would get an 11 move scramble you would have a hard time finding that optimal solution in 15 seconds. Even in 1 hour it would be tough.
There was a 4 move scramble on 2x2x2 and only one person noticed it!


----------



## Stefan (Mar 19, 2008)

AvGalen said:


> There was a 4 move scramble on 2x2x2 and only one person noticed it!


And I believe even he noticed it only afterwards.


----------



## Stefan (Mar 19, 2008)

Oh and the solved state is *not* a random state per se. The term "random state" is just an abbreviation for something like "randomly produced state" and thus only makes sense in the context of a producer, for example Cube Explorer.

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).

I somewhat remember we had a discussion and analysis about the quality of Cube Explorer scrambles a few months ago. Possibly at the yahoo group, though. Does anyone remember?


----------



## Bryan (Mar 19, 2008)

AvGalen said:


> 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.


----------



## alexc (Mar 19, 2008)

8 minutes per cube is a little extreme. I think 10 or 11 is more reasonable. For multi I mean


----------



## Pedro (Mar 19, 2008)

about the 8 mins/cube rule:

I just went to the results page, and here are the 28 first ranked (the ones who got all cubes correct)

Name - number of cubes - under 8 min/cube?

Dennis - 10 - NO
Istvan - 7 - NO
Rafal - 6 - YES (2 seconds)
Oliver - 6 - NO
Clement - 5 - NO
Constantin - 5 - NO
Stefan - 5 - NO
Rowe - YES
Milan - NO
Bastien - NO
Kai - 3 - YES
Bernett - 3 - NO
Kare - 3 - NO
Eric - 3 - NO
Andy - 2 - YES
Edouard - 2 - YES
Leyan - 2 - YES
Sinpei - 2 - YES
Daniel - 2 - NO
Piotr - 2 - NO
8 more - 2 - NO

so, just 7 out of 28, which is just 25%...

I think 8 minutes is too short...10 would be good


----------



## tim (Mar 19, 2008)

On the other hand, i think many of these guys would've gotten sub-8 per cube, if they knew that rule.


----------



## Dene (Mar 19, 2008)

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 (Mar 20, 2008)

# 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 (Mar 20, 2008)

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 (Mar 20, 2008)

i wub the new multi-blind change for obvious reasons


----------



## Lucas Garron (Mar 20, 2008)

Dene said:


> 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 (Mar 20, 2008)

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 (Mar 20, 2008)

Bryan said:


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


 
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 (Mar 20, 2008)

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


----------



## Bryan (Mar 20, 2008)

AvGalen said:


> 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 (Mar 24, 2008)

Bryan said:


> AvGalen said:
> 
> 
> > 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.
> ...


 
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


----------

