[Help Thread] FMC Discussion

[irontwig]

4 moves for 4 corners, that's just silly. Why does the insertion finder do the worse insertion first though? Edit: Now I think I understand why; it just tries every insertion, and since the 5-move cancelling insertion is earlier in the skeleton it'll find that combination first rather than a human who would do the best insertion and then go searching for another one.

 

[Cubenovice]

4 moves for 4 corners, that's just silly. Why does the insertion finder do the worse insertion first though?

With the frame being 19 moves I did not expect to improve on Sebastien's solution that's why I did not bother to look for the insertions myself...
lets say that I was pretty surprised

 

[Sebastien]

4 moves for 4 corners is really crazy I don't think I would have even looked for insertion for that skeleton if I'd found it (I had the 26 move solution after 10-15 minutes).

I like your start a lot btw!

Premoves: F U'
2x2x3: U L' B2 U2 F2 U
5 corners: D2 L' F U L U' F' L2 (can result in a 25)
or: D2 L' F L2 F' D' L D (can result in a 24)

 

[Pyjam]

Even more crazy : 6 moves for 6 corners. My solution : Patrick Jamet.

 

[Cubenovice]

4 moves for 4 corners is really crazy I don't think I would have even looked for insertion for that skeleton if I'd found it (I had the 26 move solution after 10-15 minutes).

I like your start a lot btw!

Premoves: F U'
2x2x3: U L' B2 U2 F2 U
5 corners: D2 L' F U L U' F' L2 (can result in a 25)
or: D2 L' F L2 F' D' L D (can result in a 24)

Getting lucky is not a crime

I liked this start too, consider it a revenge for #&$#@! ing up my premoves at the Zune open.

Even more crazy : 6 moves for 6 corners. My solution : Patrick Jamet.

Depends how you look at it:
# moves per piece: tie
# moves for two cycles: Insertion Finder wins

 

[Pyjam]

Depends how you look at it:

My first skeleton was : R' B' F (D' R U' R') U L D' R B' R' B' D U2 L' U F2
Then I spotted the half commutator in parenthesis, and I changed it for : R' B' F (R U' R' D') U L D' R B' R' B' D U2 L' U F2
This permutes 3 corners and removes one that was in the right place with bad orientation.
So in fact, there was 6 moves for 3 cycles, the first one with 8 moves cancelled, 18 moves cancelled in total.

On a side note, as the responsible of the weekly FMC on another forum, I don't think the Insertion Finder is a good thing.

 

[irontwig]

Well, imho inserted 3-cycles are pretty trivial and mechanical after you done a few. The difficult art of FMC is more of creating skeletons and doing more exotic insertions. Not to mention that online FMC is honesty based anyway.

 

[Cubenovice]

On a side note, as the responsible of the weekly FMC on another forum, I don't think the Insertion Finder is a good thing.

Now that this tool exists it does make me wonder why some online sub-30 solutions have the exact same insertions as Insertion Finder...
I'm not talking about the old dogs offcourse!

 

[BQ]

On a side note, as the responsible of the weekly FMC on another forum, I don't think the Insertion Finder is a good thing.

It's not good for FMC online. We made it just because we want to know the difference between finding insertitions by ourselves and by the Insertion Finder. It searchs for the fewest moves and always cancels many moves.

 

[Pyjam]

Maybe it should be good to add a blacklist of scrambles for the week.

 

[cuBerBruce]

Maybe it should be good to add a blacklist of scrambles for the week.

I think you're proposing that the existing insertion finder web site checks the entered scramble against scrambles of known active competitions. This would require the implementers of the web site to actually implement this and somehow keep the blacklist current (which would be perhaps quite a bit of extra hassle). Besides that, people could use equivalent scramble, symmetry, inverse, and cyclic shift tricks to bypass the blacklist.

 

[Sebastien]

Now that this tool exists it does make me wonder why some online sub-30 solutions have the exact same insertions as Insertion Finder...

At first I thought as well that the existence of that tool might be rather bad. But I really like it now to check if the insertions I found where optimal or not. It is also nice for testing skeletons for insertions just for interrest after an attempt is finished.

 

[palash_du]

Can anyone give me a link to this insertion finder?

I searched but did not get anything!

 

[Jakube]

Can anyone give me a link to this insertion finder?

I searched but did not get anything!

http://if.qiyuuu.com/?lang=en

 

[Ickenicke]

I will start practising FMC.

I understand blockbuilding and stuffs until the last corners.

I have read somewhere that you only need 8-moves commutators. But I can't understan how that does work, and where I can find those? How many are they?

 

[irontwig]

It's a bit silly counting how many possible ones there are since they are basically the same thing, e.g: R U R' (Inserting one corner) D2 (Adjusting layer) R U' R' (Inserting another one) D2 (Adjusting layer back)

 

[cuBerBruce]

I have read somewhere that you only need 8-moves commutators. But I can't understan how that does work, and where I can find those? How many are they?

At least according to my analysis, I get these numbers.

Considering symmetrical variations (including mirroring, but not including taking the inverse), there are essentially 24 different 3-cycle cases of corners. Of these 24 cases, 11 have an 8-move maneuver. Of those 11 cases, seven have two distinct optimal maneuvers. The other four (out of the 11) cases have one 8-move maneuver each. So there are 18 essentially different 8-move corner 3-cycle maneuvers covering 11 distinct cases.

F' L' F R' F' L F R
R B L' B' R' B L B'
F' D' F U F' D F U'
L' F R F' L F R' F'
L D' L' U L D L' U'
U' R' D' R U R' D R
F' L' F R2 F' L F R2
R2 D L2 D' R2 D L2 D'
F' D2 F U F' D2 F U'
L D2 L' U L D2 L' U'
U' F D' F' U F D F'
D' R2 D L2 D' R2 D L2
L2 F R F' L2 F R' F'
F' D F U F' D' F U'
U' R' D2 R U R' D2 R
U' F D2 F' U F D2 F'
U2 B' D B U2 B' D' B
L D' L' U2 L D L' U2

 

[Mike Hughey]

Wow, Bruce, that's really interesting. I have noticed that often there are two different 8-move solutions, but I never knew the statistics - it turns out that it's often true. And I've never noticed a case with 3 distinct solutions, and now I guess I can assume that's because there aren't any. I always wondered.

By the way, I thought people here might like to know that I got my best ever fewest moves solve today on the weekly competition 2012-18 scramble: 23 moves! I think it may not be so much that it was a lucky scramble as it was that I got a lucky solve (I definitely got very lucky), but I'm interested in seeing what other people will come up with.

 

[Cubenovice]

My quest for a sub 30 Human Thistlethwaite solve has ended!

Scramble 1 of the speedcubers.de weekly competition:

scramble
R2 B2 L2 D B2 R2 D B2 L2 B2 D2 F' R U2 B' U F' R F' U' F' U'

inverse
U F U F R' F U' B U2 R' F D2 B2 L2 B2 D' R2 B2 D' L2 B2 R2


F' B' - Edge orientation
switch to inverse with premoves F B
. L' R D R' U2 D L' D L : - Corner orientation
U' L2 - corner cycle would pair up corners (solve with random commutator, insert cycle later)
D' F2 B2 - bring corners to correct layer, leaves edge cycle and edge 2+2 swap
F B - undo premoves at this stage cancels 2 moves

insertions:
. pair swap U2 L2 U2 L2 U2 L2 cancel 1 move
: edge cycle L2 + U' D F2 D' U cancel 3 moves
+ corner cycle L2 U' R2 U L2 U' R2 U cancel 3 moves

final solution for inverse scramble
U2 L2 U2 L2 U2 L R D R' U2 D L' D L U' R2 U L2 U' R2 D F2 D' L2 D' F' B'

for regular scramble:
B F D L2 D F2 D' R2 U L2 U' R2 U L' D' L D' U2 R D' R' L' U2 L2 U2 L2 U2 = 27 HTM


And congratulations Mike!!!

My quest for a sub 30 Human Thistlethwaite solve has ended!

B F D L2 D F2 D' R2 U L2 U' R2 U L' D' L D' U2 R D' R' L' U2 L2 U2 L2 U2 = 27 HTM

LOL at the edge insertions of insertionfinder:
The Scramble：U F U F R' F U' B U2 R' F D2 B2 L2 B2 D' R2 B2 D' L2 B2 R2
Your Skeleton：L' R D R' U2 D L' D L' U' D F2 D' L2 D' F' B'

1 corner 3-cycle(s) and 2 edge 3-cycle(s) insertion(s) needed

[@1] L' R D R' U2 D L' D L' U' D F2 D' L2 D' F' B'
Insert at @1: D2 B' L2 D2 R2 F' U2 R2

After the 1st insertion: D2 [@2] B' L2 D2 R2 F' U2 R' L' D R' U2 D L' D L' U' D F2 D' L2 D' F' B'
Insert at @2: L2 D2 R2 F R2 D2 L2 B

After the 2nd insertion: D2 L2 D2 R2 U2 R' L' D R' U2 D L' D L' [@3] U' D F2 D' L2 D' F' B'
Insert at @3: L2 U' R2 U L2 U' R2 U

Fewest moves: 27. 14 moves cancelled
The final solution: D2 L2 D2 R2 U2 R' L' D R' U2 D L' D L U' R2 U L2 U' R2 D F2 D' L2 D' F' B'
Runtime: 4457.424327 milliseconds

It took me a little longer but WTF inserting 8-movers for edges?

 

[BQ]

LOL at the edge insertions of insertionfinder:
The Scramble：U F U F R' F U' B U2 R' F D2 B2 L2 B2 D' R2 B2 D' L2 B2 R2
Your Skeleton：L' R D R' U2 D L' D L' U' D F2 D' L2 D' F' B'

1 corner 3-cycle(s) and 2 edge 3-cycle(s) insertion(s) needed

[@1] L' R D R' U2 D L' D L' U' D F2 D' L2 D' F' B'
Insert at @1: D2 B' L2 D2 R2 F' U2 R2

After the 1st insertion: D2 [@2] B' L2 D2 R2 F' U2 R' L' D R' U2 D L' D L' U' D F2 D' L2 D' F' B'
Insert at @2: L2 D2 R2 F R2 D2 L2 B

After the 2nd insertion: D2 L2 D2 R2 U2 R' L' D R' U2 D L' D L' [@3] U' D F2 D' L2 D' F' B'
Insert at @3: L2 U' R2 U L2 U' R2 U

Fewest moves: 27. 14 moves cancelled
The final solution: D2 L2 D2 R2 U2 R' L' D R' U2 D L' D L U' R2 U L2 U' R2 D F2 D' L2 D' F' B'
Runtime: 4457.424327 milliseconds

It took me a little longer but WTF inserting 8-movers for edges?

Check the alg of edge 2*2-cycle, it finds insertions following:

1 corner 3-cycle(s) and 2 edge 3-cycle(s) insertion(s) needed
[@1] L' R D R' U2 D L' D L' U' D F2 D' L2 D' F' B'
Insert at @1: U2 L2 U2 L2 U2 L2
After the 1st insertion: U2 L2 U2 L2 U2 L R D R' U2 D L' D L' [@2] U' D F2 D' L2 D' F' B'
Insert at @2: L2 U' R2 U L2 U' R2 U
Fewest moves: 27. 4 moves cancelled
The final solution: U2 L2 U2 L2 U2 L R D R' U2 D L' D L U' R2 U L2 U' R2 D F2 D' L2 D' F' B'
Runtime: 114513.025627 milliseconds