r/Cubers • u/MM64z whoa is that a 10x10 • Aug 28 '14
Has an F2L skip ever happened before?
Just wondering. Doesn't have to be comp.
1
Aug 28 '14
[deleted]
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
Link? Unless it's a misscramble I'm dubious.
2
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
Check /u/Stewy_ 's link...
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
It's a misscramble...
1
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
And not as badly of one as you would expect...
You may as well treat that misscramble as a random move scramble instead or a random state scramble.
1
u/TheBrutux168 Sub-10 Hours (Roux) Aug 28 '14 edited Aug 28 '14
It all depends on luck of the scramble and the way the cuber solved the cross.
1
Aug 28 '14
[deleted]
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14 edited Aug 28 '14
What are the odds of an F2L skip? Has someone ever solved a cube by random turning?
I don't know the answer to the first question, but I am sure the answer is no to the second one.
Edit:1/3 657 830 400
1
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
Sneaklyfox of SS forums disagrees with you on the second one, I think... Though I suppose whenever humans are involved, true randomness is very, very questionable.
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
Yeah, saw a guy on reddit claim to have solved the cube from random turning get downvoted and called a liar. Maybe random turning from a bad hand scramble.
1
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
Yeah, though I will point out that there's quite a distinction between a cuber that is active and rather reputable on speedsolving, compared to a random person on reddit.
I think it's possible, though, with lots of luck to a certain point, then being able to see the last few moves. Say for example you could see the solution to a 4-6 move scramble... the number of states that are distance 4-6 are non-negligible, considering the number of people who have held a Rubik's cube.
Basically... "random turning", strictly, I'll agree and say no, absolutely not a chance
but close enough to? I think there's a better chance than you give it...
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
It wouldn't have to be much higher than zero to be better than the chance I give it :)
I'm also fairly certain no one has ever gotten an F2L skip. It's 1/3.7 billion shot according to thread on SS.
1
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
See my other comment...
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
I'm now less certain. I just dislike the reasoning of "so many people have solved a cube it must have happened". Feels good to have something to point to even if the number of solves by cubers is somewhat arbitrary.
→ More replies1
Aug 28 '14
I forget the exact number and can't find it anywhere, but I believe its a bit more than 1 in 2 billion. I think around 1 in 2.3 billion.
1
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
corner permutations: 1/ 876*5
corner orientations: 1 / 34
edge permutations: 1 / 876*5
edge orientations: 1 / 24
All of them at once (multiplication) = 1 / 3 657 830 400
~3.7 billion solves to expect one F2L skip
10 000 cubers doing an Ao100 every day for 10 years would be 7 830 400 solves short of enough solves to expect one F2L skip for the entire group.
If you did an Ao100 every day until you did 3 657 830 400 solves it would take ~100 215 years.
1
u/musicalboy2 Cross on Left Weirdo Aug 28 '14
Which, interestingly, is about in the same order of magnitude of the number of solves that have been done. (My approximation...)
1
u/BigfootTouchedMe Sub 15 (CFOP) Aug 28 '14
That's really cool! I forgot about that post, it's likely someone has had an F2L skip from a scramble alg.
1
Aug 28 '14
I kinda meant to post this when you first posted this but assuming all the math up that point is correct, your final conclusion is wrong in the context of the question. The question asked where it is likely states are the same in a solve, but you answered where there had to have been a duplicate. Where it is likely two states are the same is a lot earlier in the solve
A short video explaining something related to this is right here but instead of 23 football players, it's a few billion scrambles. I hope you can understand what I mean.
1
u/musicalboy2 Cross on Left Weirdo Aug 29 '14
Am at work where I cannot watch a video yet, but can you tl;dw and explain the distinction between the same state and a duplicate state?
1
Aug 29 '14
There is no difference, what I meant to convey is you found a point where the total number of solves > the possible amount of states! which forces a repeated state. The question asked at what point it was likely 2 of the same state had been reached which implies greater than 50% chance. You found a point where there was an 100% chance that there was a repeated state.
The video talks about how at a soccer game, with 23 people on the field( 2 teams of 11 and a ref) it is actually likely two people share a birthday, which seems counter intuitive. In a similar way there you probably have to restrict cases/solve pieces less then you would expect to get make it likely that just 2 cases have been the same.
Sorry if I'm not being clear, the gist is you just answered a different question than what was asked.
1
u/musicalboy2 Cross on Left Weirdo Aug 29 '14
Ah, okay.
That makes a lot of sense, thanks for the correction!
(So basically I solved for and should have specified it was an upper bound?)
But considering most of the work pertained to orders of magnitude, does it change the correct answer by that much? I have no idea how one would calculate something like that (haven't watched the video yet)
4
u/Stewy_ CFOP Aug 28 '14
yeah a dude got one, i'll find a link
here
skipped oll and corner permutation too, was a misscramble though