[Help Thread] FMC Discussion

[theos]

At last! I finally got my first sub 30 FMC solution. I am really happy with this solution, especially since I was able to get to AB4C in just 21 moves. The scramble was from the Weekly Berkley FMC, so in case anyone is going to do it, I put it all in spoilers. I got this yesterday, but forgot to post it in this thread.
Also, I do not know if there is anything that you see that I should have thought about with this solution, but if you have any thoughts, I would be more the happy to hear them.

Spoiler: 29 move FMC Solution

Scramble: F L' R' F2 U2 L' F D2 R' U2 B' D F' B L U' D B' U2 F'

F B R2 D R' U2 R2 U'//2X2X2 [8/8]
B' L D B L'//F2L-1 [5/13]
D' B' D B2 R' B' R D //AB4C [8/21]

1st Skeleton: F B R2 D R' & U2 R2 U' B' L D B L' D' B' D B2 R' B' R D [21 moves]
Insert at &: R' D' R U2 R' D R U2 [cancels 4 moves]

2nd Skeleton: F B R2 D R2 D' R U2 R' D R' $ U' B' L D B L' D' B' D B2 R' B' R D
Insert at $: R U' L' U R' U' L U [cancels 4 moves]

Final solution:
F B R2 D R2 D' R U2 R' D U' L' U R' U' L B' L D B L' D' B' D B2 R' B' R D [29 moves]

Nice one - keep it up!

With your start I can get a slightly shorter skeleton (with the same number of unsolved corners) but the insertions are actually worse.

Spoiler: 30 moves

Scramble: F L' R' F2 U2 L' F D2 R' U2 B' D F' B L U' D B' U2 F'

F B R2 D R' U2 @ R2 U' // XCross given [8/8]
B' L D B L' // F2L-1 given [5/13]
R' * B R B2 D' B D2 // AB4C [7/20]
Insert at *: R' F' R B R' F R B' // 1 corner, from IF [4/24]
Insert at @: D' L2 D R2 D' L2 D R2 // last 3 corners, from IF [6/30]

Solution: F B R2 D R' U2 D' L2 D R2 D' L2 D U' B' L D B L' R2 F' R B R' F R2 B2 D' B D2 (30 moves)

 

[cubeshepherd]

Nice one - keep it up!

With your start I can get a slightly shorter skeleton (with the same number of unsolved corners) but the insertions are actually worse.

Spoiler: 30 moves

Scramble: F L' R' F2 U2 L' F D2 R' U2 B' D F' B L U' D B' U2 F'

F B R2 D R' U2 @ R2 U' // XCross given [8/8]
B' L D B L' // F2L-1 given [5/13]
R' * B R B2 D' B D2 // AB4C [7/20]
Insert at *: R' F' R B R' F R B' // 1 corner, from IF [4/24]
Insert at @: D' L2 D R2 D' L2 D R2 // last 3 corners, from IF [6/30]

Solution: F B R2 D R' U2 D' L2 D R2 D' L2 D U' B' L D B L' R2 F' R B R' F R2 B2 D' B D2 (30 moves)

Thank you @theos for looking at this and for the different solution. I really like to see others opinions when it comes to FMC and it helps me think about different things and to also pay attention to different things next time or just in general for the future. Thank you again for your solution.

 

[SpeedCubeReview]

What does the AB mean in AB4C?

 

[cubeshepherd]

What does the AB mean in AB4C?

"All but" so when you see AB3C it is just a short way of saying "All But 3 Corners are solved".

 

[theos]

Really nice scramble I got in practice:
R' U' F B U2 L2 B F2 R2 D2 F R2 U R B' F' D2 L2 D L F2 U R' U' F

Lots of potential from the start and everything seemed to work out so neatly to end with a 3 corner skeleton.

Spoiler: 25 moves

pseudo-2x2x2: L' F R2 B [4/4]
pseudo-2x2x3: (B' L D' L) [4/8]
2x2x3+EO: F' L [2/10]
F2L-1: F * D2 F2 [3/13]
AB3C: F D2 F' D F D' F' [6/19]
Insert corners at *: F' D2 F U F' D2 F U' [6/25]

Solution: L' F R2 B F' L D2 F U F' D2 F U' D2 F' D2 F' D F D' F' L' D L' B (25 moves)

 

[asacuber]

Tarnby cube traef scramble 2 seems to have something good. Everyone is getting pbs and best solves on it

 

[cubeshepherd]

Tarnby cube traef scramble 2 seems to have something good. Everyone is getting pbs and best solves on it

I agree, and I hope/think it would be nice to see the scramble, if someone is able to post it in a few day.

 

[arquillian]

I'm one of the people who got a PB on the second scramble at Tarnby, so here:
Scramble: R' U' F R2 D B2 D L2 F2 U' L2 R2 U L' B D' U F D B2 F2 D R' U' F
Inv Scr: F' U R D' F2 B2 D' F' U' D B' L U' R2 L2 U F2 L2 D' B2 D' R2 F' U R
On inverse:
L' F L B //2x2x1 4/4
R D R D2 L D //2x2x3 6/10
U2 R U2 R' U' //F2L-1 5/15
F' R' F R2 U' R' U F' //A3C 8/23

Skeleton (23): F U' R U R2 F' R F U R U2 R' U2 * D' L' D2 R' D' R' B' L' F' L
Insert at *: L' U L D' L' U' L D - 4 moves cancelled (IF says this is optimal)

Final solution (27): F U' R U R2 F' R F U R U2 R' U2 L' U L D' L' U' D2 R' D' R' B' L' F' L
This was the fourth best solution on this scramble, after Jakob (23) and the Egdal brothers (both 26).

I tied my official PB on the first attempt with a 39. This beat that by 12 moves. I don't really do FMC, was kinda speechless. Sadly, I DNFed the mean (only needed to sub 67 to beat official PB mean) because I'm an idiot who doesn't understand NISS properly.

 

[Sue Doenim]

This past weekly competition (week 24), I was pretty happy with my FMC attempt. I got a 31, and got my first podium, 3rd, on anything in the weekly competitions. The only part of the solve where I was a bit disappointed was in my insertion. Checking insertion finder, it showed better results, but with weird commutators I don't quite understand. Can anyone help explain them to me?

Spoiler

Scramble: R' U' F D2 L' F L' B' L' D2 B2 U L2 F U2 B2 R2 F U2 B U2 B2 R' U' F

My insertion was only three edges, but for the sake of brevity, I'll use the one skeleton and show all three insertions solving the same case in it.

Skeleton: B' U F' D2 B' L' D L' R D' L (1) D R' (2) D L D' B2 (3) R' (4) B U R2 F

1 (mine):
B' U2 D2 F D' F' U2 D2 B D
Cancels 1
Simple commutator, [B E2 B', D']

2:
R D R' B' L' F' D' F L B
Cancels 3
I think this is just a non-commutator 3-cycle, so I'm not mad I missed it.

3:
F' B U' R' U F B' R' D R
Cancels 3
This one I don't get. It boils down to [S, R' D' R], but i just can't make sense of it. I don't see the insert/interchange I recognize commutators by. Logically, S seems to be the interchange, and R' D' R the insert, but they "cross axes," as best as I can explain it.

4:
R F' B U' R' U F B' R' D
Cancels 3
This one is the same sort of thing, only this time it's [R: S, R' D' R], which, now that I think of it, is just the exact same thing as the last one.

Mostly I just want an explanation of the third one, I guess.

 

[FastCubeMaster]

Any ideas for continuing from:

Scramble: R' U' F L2 D' U2 F2 L2 D B2 L2 U2 F2 L2 B R2 F L' U2 L2 R' B' U2 B2 R' U' F

L2 D R2 F' L2 R' B' R B2 R D' R' D R' B D B2 //F2L-1 (17 moves)

Getting started in FMC (because of mental breakdown comp) and couldn't continue that scramble very well.

 

[obelisk477]

Any ideas for continuing from:

Scramble: R' U' F L2 D' U2 F2 L2 D B2 L2 U2 F2 L2 B R2 F L' U2 L2 R' B' U2 B2 R' U' F

L2 D R2 F' L2 R' B' R B2 R D' R' D R' B D B2 //F2L-1 (17 moves)

Getting interested in FMC (because of mental breakdown comp) and couldn't continue that scramble very well.

x2 y2 F R U R' U' F' y2 U2 F' U F

That leaves 3 twisted corners, and you could insert 2 comms for that for a total of 33 moves (via insertion finder).

TBH, 17 to F2L-1 isn't great, especially since you don't have full EO, so I would try to find a better start.

 

[porkynator]

My 25 from Veenendaal Open 2018

Spoiler

Scramble (inverse solution): B D2 R' L F L' D2 F' R' F L F' R F D2 L D2 L F2 L2 R2 U' R' L' U

Inverse:
B D2 R' L F //EO + square (5/5)
D2 L F2 //Line + another square (3/8)
L2 R2 U' R' //Pseudo F2L (4/12)

From here I have first switched to normal and got this backup 27:

L U' L' U2 L //F2L (5/17)
R2 D' L F2 L' D R U2 R U //LL (10/27)

But there are many possibilities. For example (on inverse):

L' U' //All but 2 edges and 4 corners (2/14)

But I didn't like this one.

* L' //3E5C (1/13)

was better. With

* = B' U' R U2 L' U L U2 R' B //Pair 3-cycle (10/23)

I got to 3 corners in 23, but there was no good insertion (even if so, I had little chances of doing better than 27).

In the end I have found this:

L' U //4E4C (2/14)

Skeleton: B D2 R' L F * D2 L F2 L2 R2 U' R' L' U

* = L' D2 + L D2 L //Conjugate and solve edges (leave 3C) (5/19)
+ = F' R' F L F' R F L' //(6/25)

You can also see the inserted part as a whole as a "conjugate and solve":

* = [L' D2 F' R' F, L] = L' D2 F' R' F L F' R F D2 L

 

[guysensei1]

Building blocks incompatible with your EO isn't always bad...

R' U' F R L2 U' R2 B2 D2 F2 U2 F2 U F2 B L2 B2 U B D' R D' F R' U' F

F U2 D' R//EO (4/4)
(L2 D)//2x2x2 (2/6)
B' R2 B2 U2 B U' B2 U//F2L on the wrong axis (8/14)
F2 U2 B U B' U2 F U' F//LL (9/23)

 

[alexela]

FMC, method ROUX (Week 182): 22 STM (26 HTM)
B' L2 B2 D L2 R2 U R2 U B2 L2 U' L' D B U2 L U2 F2 L2 D2

y' z //Inspection
u' S2 //Pseudo FB (2/2)
M2 U' r2 //Pseudo SS (3/5)
U2 M2 U //Pseudo SB (3/8)
R2 U B U' B' R' //NMCLL (6/14)
U M' U //EO+LR (3/17)
R2 U2 l2 U2 R //The Rest of the Cube (5/22)

Solution: F' U2 D2 R2 L2 B' L2 F2 R2 L2 B R2 B D B' D' R' B R' L U R2 U2 R2 D2 R (26 moves)

 

[SpartanSailor]

During fewest moves event... can you manipulate the cube to test your solution or to try our move sequences?

 

[Duncan Bannon]

@SpartanSailor If I understand you right, that is completely legal.

 

[DGCubes]

During fewest moves event... can you manipulate the cube to test your solution or to try our move sequences?

Yes, you can. You are allowed to bring 3 cubes, and you can do just about whatever you want with them for the full hour. The relevant section of the regulations is Article E.

 

[ChrisCuber123]

solutions from my 26.67 mean at Maryland 2018 yesterday
scrambles (generated with cube explorer):
1. U' B2 L' D R2 U' B' U2 R' F' D' L' F2 B2 U D2 F2 U' D2 F2
2. U L' F' D2 R L' U B2 D L F B2 L2 U2 D2 F2 B U2 F L2
3. F R F D2 B2 L B L2 D R L D2 L' F2 R' U2 B2 L2 F2 R2

solutions:

Spoiler

F' (R U L2 F) // EO
(B2 L D' R') // 2x2x2
U' R U' R' U L' U L // good 6c
skeleton: F' U' R U' R' U L' U L R D L' B2 F' * L2 U' R'
*: F ^ R F' L' F R' F' L (cancels 3)
^: B R F' R' B' R F R' (cancels 5 lmoa)
final solution: F' U' R U' R' U L' U L R D L' B' R F' R' B' R L' F R' F' L' U' R' (25)

Spoiler

U' L2 U2 L // EO+square
(U' R2 U2 F U2 B2) // 2x2x3
(B D' B' L2 D2 L2) // bad 6c
at this point I tried to find a comm that canceled 6-8 moves and reduced the skeleton to 4/5c and found this:
skeleton: U' L2 U2 L' D2 L2 B D B * U2 F' U2 R2 U
*: B' D' B U2 B' D B U2 (cancels 7, 15 to 5c)
5c skeleton (here come the shitty insertions): U' L2 U2 L' D2 L2 B2 U2 ^ B' * D B F' U2 R2 U
*: B R B' L2 B R' B' L2 (cancels 2)
^: U' B U F2 U' B' U F2 (cancels 1)
final solution: U' L2 U2 L' D2 L2 B2 U B U F2 U' B' U F2 R B' L2 B R' B' L2 D B F' U2 R2 U (28)
optimal for this skeleton was 27, 1 cancel nesting a 3 cancel

Spoiler

(U2 F2 D2 B) // EO
(D2 U R') // 2x2x2
(F2 L2 D L) // 2x2x3
(F2 L D L' D' R' D R D R' D' R) // L3C
(R' D L2 D' R D L2 D') // comm, cancels 4
final solution: D L2 D' R' D L2 R D' R' D' R D L D' L' F2 L' D' L2 F2 R U' D2 B' D2 F2 U2 (27)

Ryan DeLine's 24:
D F2 D' F2 D // 2x2x2
U * R B2 U B // 6e3c (lol)
*: U' R B2 U // solve stuff
B' D' R' D R B R2 // L3C in 18 (more lol)
insertion cancels 2

 

[Neuro]

So I got this scramble and was able to get to EO2x2x3 pretty easily but I’m not entirely sure how to end the solve. Suggestions?

B’ F D2 U2 L2 F’ U2 F U’ B R U’ L’ R’ B’ U2 B2 D’ B

R’ B2 D’ L’ D’ R2 U’ L2 U2 L’

I did find L5C redux in 5 moves but I don’t really like L5C lol

B2 U B2 U B’

 

[SpartanSailor]

Yes, you can. You are allowed to bring 3 cubes, and you can do just about whatever you want with them for the full hour. The relevant section of the regulations is Article E.

So you are permitted to test your solution or move count by manipulating one of the 3 self-supplied cubes.

Interesting. Thanks!