Throwing out scrambles in competitions?

[Kirjava]

So I hear that scramble filtering is gaining some steam again.

Can we reopen the debate before something like this ends up happening again without community input?

I still see no good reason for filtering.

 

[Stefan]

So I hear that scramble filtering is gaining some steam again.

Where?

 

[Kirjava]

IRC told me that people are planning on implementing it

 

[Stefan]

IRC told me that people are planning on implementing it

"people" as in Ron, Tyson & co or as in cubegod0815, anonymousmoron123 & co?

 

[Cubenovice]

"people" as in Ron, Tyson & co or as in cubegod0815, anonymousmoron123 & co?

As in Ron mentioning it during N8W8 competition last week.

I personally heard him say it.

 

[Mollerz]

As in Ron mentioning it during N8W8 competition last week.

I personally heard him say it.

Indeed. We were doing 2x2 and I jokingly asked Lars if he'd generated a 1 move 2x2 scramble and then Ron told Daniel, Rob and I that scramble filtering would be brought in. No 2x2 scrambles shorter than 4 moves, clock shorter than 9, 3x3 shorter than 16 (If I remember correctly), but also for pyraminx and square-1 as well but I can't remember the amounts on those.

 

[Kirjava]

Ron seems to be dictating this as if it's going to happen.

I hope he has good justification for doing so.

 

[uberCuber]

These numbers seem so arbitrary. For 2x2, I can execute (with official start/stop) R U' R' U R faster than R2 U2 R2.
For 3x3, how would a 15-move scramble have a significant impact over a 16-move one? It's not like speedsolving methods come anywhere close to optimal. Honestly, I just did some 10-move scrambles, and don't notice any difference in the quick inspection I would use in a competition; my CFOP solutions were largely the same level of difficulty as any regular scrambles I've used.

 

[Mollerz]

These numbers seem so arbitrary. For 2x2, I can execute (with official start/stop) R U' R' U R faster than R2 U2 R2.
For 3x3, how would a 15-move scramble have a significant impact over a 16-move one? It's not like speedsolving methods come anywhere close to optimal. Honestly, I just did some 10-move scrambles, and don't notice any difference in the quick inspection I would use in a competition; my CFOP solutions were largely the same level of difficulty as any regular scrambles I've used.

3x3 scrambles I would presume would be done for FMC primarily.

 

[Mike Hughey]

I would like to think that if there is a minimum scramble length, there will be a somewhat sensible mathematical justification for the minimum scramble sizes which makes sense of the lengths chosen for each puzzle. I would be disappointed if this was not done.

I think a 4-move 2x2x2 limit seems inconsistent with a 16-move 3x3x3 limit. 16 moves seems quite reasonable for 3x3x3, since that eliminates a very small percentage of the possible scrambles, but if we do that, you'd think we'd want to go with a larger number of moves for 2x2x2, so that we eliminate an equally small percentage of the scrambles for that puzzle.

 

[Bob]

There is justification for a 4 move limit on 2x2 and it does not seem arbitrary to me. It could be that 4 moves is the least number of moves we have used for a 2x2 scramble to date (AFAIK). The Board has thrown out a 2-move scramble, so I would expect the lower bound to be either 3 or 4 moves. Since 3 moves has never occurred so far, we're not being unfair to anybody if 3 move scrambles are not allowed. If the lower bound were more than 4 moves, this would create a situation in which the current records become harder to break because the circumstances in which they were set cannot be replicated (ie - a 4 move scramble).

I am speculating only and do not have any justification for any of the other move counts on the other puzzles.

 

[Kirjava]

The Board has thrown out a 2-move scramble, so I would expect the lower bound to be either 3 or 4 moves.

Why can't we just treat this as a mistake? We don't have to filter forever just because we did it once based on a poor decision.

 

[Bob]

Why can't we just treat this as a mistake? We don't have to filter forever just because we did it once based on a poor decision.

I don't view it as a mistake. I agree that a two-move scramble is too "easy."

Now before you argue with me about what an "easy" scramble is, I'll admit I have no good definition for this. Obviously a scramble can be "easy" without having a low move count, such as Sune or something, but I have no good definition for easy other than <4 moves to solve, and that's kind of a crappy definition.

 

[Kirjava]

I don't view it as a mistake. I agree that a two-move scramble is too "easy."

I fully agree that a 2 move scramble is easy.

However, I don't see why this means it has to be removed.

 

[Bob]

I fully agree that a 2 move scramble is easy.

However, I don't see why this means it has to be removed.

Not just easy, but TOO easy. You're right--it doesn't HAVE to be removed. But I think it should be.

It's scrambles like those that make the single records/rankings meaningless. I would not mind filtering if rankings were not kept for certain categories (2x2 single & pyraminx single, for example).

By throwing out scrambles less than 4 moves on 2x2, we're only eliminating 384 scrambles out of ~3.7 million. I don't think as a community we lose anything my disallowing those scrambles. The odds of those scrambles occurring anyway are very low, but I don't like the idea of them coming up at all. Where would you draw the line? If the scramble was only 1 move, would that be okay? What about a pyraminx solve in which only the tips are scrambled. What about a scramble that brings the cube back to the solved state?

 

[Erik]

Not just easy, but TOO easy. You're right--it doesn't HAVE to be removed. But I think it should be.

It's scrambles like those that make the single records/rankings meaningless. I would not mind filtering if rankings were not kept for certain categories (2x2 single & pyraminx single, for example).

By throwing out scrambles less than 4 moves on 2x2, we're only eliminating 384 scrambles out of ~3.7 million. I don't think as a community we lose anything my disallowing those scrambles. The odds of those scrambles occurring anyway are very low, but I don't like the idea of them coming up at all. Where would you draw the line? If the scramble was only 1 move, would that be okay? What about a pyraminx solve in which only the tips are scrambled. What about a scramble that brings the cube back to the solved state?

Then why do we even keep track of fastest single for 2x2 and pyraminx? The records nowadays are already impossible to break on a normal scramble, they don't mean anything.

 

[Kirjava]

You're right--it doesn't HAVE to be removed. But I think it should be.

I still don't see a good reason why.

It's scrambles like those that make the single records/rankings meaningless.

So what? Single records are already meaningless compared to average results for this event - I don't see how filtering would suddenly make them meaningful.

How will allowing 4 move scrambles but removing 2 move scrambles suddenly make the event a pinnacle of integrity?

You're just changing the 2x2x2 single WR from "who can do 2 moves the fastest" to "who can do 4 moves the fastest". How does this fix *anything*?!

Where would you draw the line? If the scramble was only 1 move, would that be okay? What about a pyraminx solve in which only the tips are scrambled. What about a scramble that brings the cube back to the solved state?

Any non-solved state is a scramble.

 

[Cubenovice]

You're just changing the 2x2x2 single WR from "who can do 2 moves the fastest" to "who can do 4 moves the fastest". How does this fix *anything*?!

- it lowers the amount of easy scrambles
- 4 move solutions take longer to perform and it requires more puzzle insight to find the solution during inspection.

And for those who do not want filtering because it might rob them of an awesome single: You could still get a Sune or corner cycle...

But why the focus on 2x2 and pyraminx?
Imagine a 3x3 off by just three corners…

 

[Kirjava]

- it lowers the amount of easy scrambles

This is a /bad/ thing.

- 4 move solutions take longer to perform and it requires more puzzle insight to find the solution during inspection.

You can't possibly say that 3 moves is trivial yet 4 moves is not.

And for those who do not want filtering because it might rob them of an awesome single:

This is not why we do not want filtering.

But why the focus on 2x2 and pyraminx?
Imagine a 3x3 off by just three corners…

So what? If we filter to 16 moves, cases where the entire F2L is solved are still valid.

 

[TimMc]

It seems like a massive waste of time to get people filter scrambles on the day. Why not apply a filter to the scramble programs instead?

Who is filtering the scrambles on the day? Is it another competitor from the first group who's scrambling for the second group? (i.e. they're crying about an a easy cross that they missed out on)

I throw out scrambles all the time; after they've been used and the sheet is no longer needed (PDF backup).

Tim.