
A Historic Day for the World of Competitive Rubik’s Cube Solving - ohjeez
https://medium.com/@jblake17/a-historic-day-for-the-world-of-competitive-rubik-s-cube-solving-33a92a5f3d1c#.x89rnc6y7
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callesgg
I assume the time depends very much on the initial state.

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baddox
I wonder how they set the initial state. I think it's fairly easy to calculate
the minimum number of moves required to solve from a given state, so you'd
think they would control for this.

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harryh
It is, in fact, not easy at all to calculate that.

[https://en.wikipedia.org/wiki/God%27s_algorithm](https://en.wikipedia.org/wiki/God%27s_algorithm)

(There isn't as much info as there should be on that Wikipedia page but it was
an open area of research for decades.)

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baddox
Isn't it though? I thought the hard part was proving the minimum number of
moves that can solve all possible initial states. Korf's algorithm and several
subsequent improvements seem to be able to find the minimum number of moves to
solve any given initial state.

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harryh
A yes. You are correct.

Finding minimum # of moves from a single state = not so hard.

Finding the worst possible state (the state where the minimum # of moves is a
maximum) = pretty hard, though now solved.

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sandworm101
There is a point at which the elites of any activity become so proficient that
meaningful differences between them disappear. Competitions are then won based
on factors seemingly outside the nature of the activity. These rubik solvers
seem to be at a point.

Looking at the comments on this thread few talk of the actual solving. Most
are concerned with the circumstances of the competition, I think because most
here realize the differences between competitors are so slight that one must
look to the competition rather than the competitive act to determine validity.

So I offer this
alternative:[https://www.youtube.com/watch?v=B5Zi054Fa5k](https://www.youtube.com/watch?v=B5Zi054Fa5k)

By increasing the underlying difficulty of the task to the point that even the
elites make many mistakes during competition, the focus returns to the
underlying skill.

And:[https://www.youtube.com/watch?v=hOilnrGrKsY](https://www.youtube.com/watch?v=hOilnrGrKsY)

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level3
Few comments are about the solving because few commenters are actually cubers.

If you look at discussions of this on actual cubing forums, then you'll see
that the differences between competitors are actually significant.

Edit: As a direct example of competitors making mistakes, Etter's 4.9s solve
could actually have been trivially improved if he had done a U instead of U'
U' U' on the 2nd pair.

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mathgenius
Rubik's cube always gets me thinking about group theory. Eg. [http://www.gap-
system.org/Doc/Examples/rubik.html](http://www.gap-
system.org/Doc/Examples/rubik.html)

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zuck9
Relevant TED Ed video:
[https://youtu.be/FW2Hvs5WaRY](https://youtu.be/FW2Hvs5WaRY)

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jpiabrantes
The human reaction time is about 0.1 seconds. They shouldn't use a manual
chronometer to measure these results 4.9+/-0.1 is the difference between a
world record and a good score.

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level3
I believe WCA officially uses StackMats for the timing. Timer starts when you
lift your hands from the touch pads and stops when you return them to the
pads.

This isn't perfect either but it doesn't rely on someone else's reaction time.

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bpicolo
Correct.

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zuck9
This happened with the 2x2 cube too, 3 world records in the same competition:
[https://www.worldcubeassociation.org/results/events.php?even...](https://www.worldcubeassociation.org/results/events.php?eventId=222&regionId=&years=&show=100%2BPersons&single=Single)
(Trentin Open 2011)

The scramble was too easy, required only 4 moves.

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dudus
WRs of people solving Rubik's cubes with their feet is a thing these days.
These seem much more skill based.

[https://youtu.be/DDWdSWfUAeo](https://youtu.be/DDWdSWfUAeo)

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jonahx
It looks like he picks it up and examines it for a while, then puts it down.
The timed solving starts only when he picks it up again -- is this correct? Is
there a time limit to the examination stage?

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rosstex
15 seconds

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phjesusthatguy3
The video embeds on this story say they're stopped because I have Do Not Track
set on my browser. They imply that if I do watch the videos, it's my own damn
fault if I get tracked. So thanks for reminding me to never visit medium.com,
I guess.

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lambda
Hmm? This is Medium doing a reasonable thing.

They comply with Do Not Track, but people can embed videos on sites that do
not comply. Here they do a reasonable thing, and show a message to people with
"Do Not Track" enabled, letting them know that they can still click through
and see the video, but the site they are directing you towards might track
you.

Medium is just a blog hosting platform, as far as I know they don't control
the content that gets posted. What would you prefer they do; not allow
embedding YouTube videos? Not warn you that the linked content tracks you?

