[Help Thread] FMC Discussion

[Isaac Lai]

Weekly Comp

Spoiler

R U' R' F L2 U' //2x2x2
D' R D F D' //2x2x3
R F' D' F' D //F2L-1
R2 F R2 F' R2 F R2 F' R //AB3C
U F U' B U F' U' B' //ZBLL/commutator/fail insertion
33 moves

This is the first attempt where I actually tried to use an insertion, and I wasn't really sure how to go about doing it. Therefore, I missed the optimal insertions (which would have cancelled 3 moves). I did manage find a few insertions in the middle of the skeleton though, but they didn't cancel any moves. Pretty disappointing, because after finding a 24 move skeleton I was sure it would be a PB.

EDIT: Lol exactly the same as Jaysammey's skeleton

 

[G2013]

Skeleton to 7 unsolved pieces in 15 moves, couldn't find anything good so I did insertions, 9 cancellations and optimal were 10

Spoiler

Scramble: B' F2 R U' B2 D' F' L2 B' D2 L' F2 R D' L2 U2 L R' U B'
Inverse: B U' R L' U2 L2 D R' F2 L D2 B L2 F D B2 U R' F2 B

F R2 //2x2x1
D F' //2x2x1 and pair
(L2 U' F U F U2 L2) //2x2x3
L B L' //Pair
(B) //To L3E + L4C

Skeleton:
F R2 D F' L B L' B' L2 U2 F' U' F' U L2 (15)

Edges insertion:
F R2 D F' L B L' B' L2 U2 F' U' F' (F' R2 F M F' R2 F M') U L2 = 15+10-1 = 24
Skeleton: F R2 D F' L B L' B' L2 U2 F' U' F2 R2 F R L' U' R2 U L R' U L2 (24)

Corner insertion no. 1:
F R2 D F' L B L' (L' F L B' L' F' L B) B' L2 U2 F' U' F2 R2 F R L' U' R2 U L R' U L2 24+8-4=28->this
Skeleton: F R2 D F' L B L2 F L B' L' F' L' U2 F' U' F2 R2 F R L' U' R2 U L R' U L2 (28)

Corner insertion no. 2:
F R2 D F' L B L2 F L B' L' F' (D' L' U2 L D L' U2 L) L' U2 F' U' F2 R2 F R L' U' R2 U L R' U L2 28+8-4=32->this

Final solve: F R2 D F' L B L2 F L B' L' F' D' L' U2 L D L' F' U' F2 R2 F R L' U' R2 U L R' U L2 (32)

Could someone find a new continuation without the use of insertions so I can learn? Thanks!

 

[guysensei1]

(Question)
Say I got this scramble: R' U' F L2 U' F U D F' R B' U2 B2 D R L2 D2 F2 U R2 U' L2 F2 R' U' F
Right away I see F' U R F2//2x2x2

But that is undoing the first 4 moves of the scramble, am I disallowed from using this start, even with adequate explanations? I found this: "Guideline E2e++) Example of solutions that should result in a disqualification of the attempt (DNF): solutions beginning with the same 4 or more moves as the inverse scramble sequence." But that seems rather harsh...? It's a perfectly reasonable explanation to undo the first 4 moves in this case...

What is the exact threshold for 'too similar' anyway? It's not clearly written in the regulations or guidelines.

By the way it was a fun exercise with NISS and cubeexplorer to generate that scramble for discussion

 

[AlphaSheep]

(Question)
Say I got this scramble: R' U' F L2 U' F U D F' R B' U2 B2 D R L2 D2 F2 U R2 U' L2 F2 R' U' F
Right away I see F' U R F2//2x2x2

But that is undoing the first 4 moves of the scramble, am I disallowed from using this start, even with adequate explanations? I found this: "Guideline E2e++) Example of solutions that should result in a disqualification of the attempt (DNF): solutions beginning with the same 4 or more moves as the inverse scramble sequence." But that seems rather harsh...? It's a perfectly reasonable explanation to undo the first 4 moves in this case...

What is the exact threshold for 'too similar' anyway? It's not clearly written in the regulations or guidelines.

By the way it was a fun exercise with NISS and cubeexplorer to generate that scramble for discussion

Definitely an interesting and important question.

I think the whole debate on what's defines "too similar" was what started the debate which led to the scramble change in the first place. Linus's DNFed attempt had 11 moves in common with the inverse scramble, which is quite extreme, but he had a perfectly reasonable explanation for each of those steps.

Now with the new scrambles, since the last 3 moves are always the same it doesn't help to use them to derive a solution. That's what lets the regulations set a "fair" threshold. 3 moves in common is OK, 4 moves is a DNF. Having a reasonable explanation is irrelevant since for some scrambles, it's theoretically possible to give a reasonable explanation for the entire inverse scramble. What would happen in a case like that?

This case is difficult though. The main choice for the extra moves was so that the scramble couldn't be used to do work out an easy EO which is something only advanced FMC solvers would be likely to try. Its much harder to avoid lucky blocks, and I'm not sure if any good way to avoid it. In this case those 4 moves would be obvious to almost anyone. Even someone just doing CFOP may see them as an easy Xcross. A person like that quite possibly wouldn't think that those 4 moves wouldn't be allowed. I'd feel horrible DNFing an otherwise valid 50+ move CFOP solution. It's what the guidelines say though, so there's not much room for flexibility.

Is just my opinion based on the discussions that took place when the scrambles changed. I'd really like to know what more experienced delegates or WRC members think.

 

[Laura O]

This guideline uses the word "should", which means...
"that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course."

So in the rather unlikely case that the first 4 moves of the inverse scramble generate an obvious block (or something similar) this would not necessarily be a DNF.

 

[guysensei1]

In this case those 4 moves would be obvious to almost anyone.

What if undoing the 4 moves of the scramble gives some more obscure start like solving all corners or something else? I suppose this would be up to the delegate at the competition, but it is possible that the delegate may not consider them 'obvious' when others do.

 

[AlphaSheep]

What if undoing the 4 moves of the scramble gives some more obscure start like solving all corners or something else? I suppose this would be up to the delegate at the competition, but it is possible that the delegate may not consider them 'obvious' when others do.

Yeah, it's a problem with no easy solution. Some delegates have a really good understanding of FMC, but others don't know much about FMC techniques at all.

 

[Laura O]

What if undoing the 4 moves of the scramble gives some more obscure start like solving all corners or something else? I suppose this would be up to the delegate at the competition, but it is possible that the delegate may not consider them 'obvious' when others do.

Yes, the best solution for this would rather be to ask other degates and the WRC.

 

[biscuit]

This may be better suited to the OQOA regulations thread, but we're already talking about FMC rules so...

I can't remember reading anything about how fast FMC scrambles must be checked. Would it be permissible to just check for podium, then check the rest of the solutions after the fact?

 

[guysensei1]

Weekly fmc, 29

Spoiler

Scramble:
R2 B' R2 U2 D' B2 L' U2 D2 B R B' L' R D U2 R' D' B2 U2

F R L F D2//2x2x2
L U2//2x2x3
D' L D2 F D'//EO
L F2 L2 F'//F2L-1
Switch to inverse
L F2 L' F'//All but 3 pairs
L//setup
U F' L' F' L F U'//WV alg (actually a pair 3 cycle)
L'//undo setup

Final: F R L F D2 L U2 D' L D2 F D' L F2 L2 F' L U F' L' F L F U' L' F L F2 L' (29)

 

[Rcuber123]

Weekly FMC: 25

Spoiler

Scramble:
R2 B' R2 U2 D' B2 L' U2 D2 B R B' L' R D U2 R' D' B2 U2

L F L (3/3) 2x2x1
R F D' F' U2 F D' (7/10) 2x2x3
L F' U' F U (5/15) many blocks
F' L F (3/18) all but 3 blocks
F D' L' D L D F' D' (8-1=7/25) block commutater

 

[TheCoolMinxer]

Cubelonia 33.33 mean

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

D R' B' F2 D2 R2 //223
B' L' B L U' R B' R' B U2 B U2 B' //F2L finish
L2 D2 L' U2 L D2 L' U2 L' //ZBLL -> 28 moves

#2 R' U' F L' F2 L2 B2 F2 L' D2 L D2 R2 B2 F L2 U B' R' F' L2 U' B R' U' F

(U' F U R D' R2) //222
(U L' B' U' L' U' L2 U2 L') //F2L-2
(B' L B' L' R B' R' B' L' D L2 B L' B' D L2 D R D' L2 D R' D B2) //F2L cancelled in OLL cancelled into A perm

Solution: B2 D' R D' L2 D R' D' L2 D' B L B' L2 D' L B R B R' L B L' B L U2 L2 U L U B L U' R2 D R' U' F' U -> 39 moves

#3 R' U' F R2 D2 F' U2 L2 B2 D2 U2 L2 B' R2 D' R D' F' D2 B2 D2 L' D R' U' F

(U' R L2 U' F D') //cross
(U' F U' F' U F' U' F R' U R) //F2L-1
(U2 L U' L2 B L B D' F R2 F' D B U2 B U') //F2L finish cancelled into ZBLL

Solution: U B' U2 B' D' F R2 F' D B' L' B' L2 U L' U2 R' U' R F' U F U' F U F' U D F' U L2 R' U -> 33 moves

28, 39, 33 -> 33,33 mean! So happy with this, I'll never have to practise FMC again!

 

[Bubtore]

Welcome to Germany where you do a 26.66 mean and you're not on podium ... (Swiss NR mean btw.)

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

Spoiler

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

D R' B' L F2 D2 R2 // 223
(U R' U2 R B U2) // L4C

Skel // D R' B' L F2 D2 * R2 U2 B' R' U2 R U' - 13
* D' L D + R' D' L' D R
+ D2 R U R' D2 R U' R'

My thoughts on this : I've spent to much time on that L4C, thus I missed to look for other good skeletons.

Solution // D R' B' L F2 D L D' R U R' D2 R U' R2 D' L' D R' U2 B' R' U2 R U' - 25 Moves

Scramble // R' U' F L' F2 L2 B2 F2 L' D2 L D2 R2 B2 F L2 U B' R' F' L2 U' B R' U' F

Spoiler

I // F' U R B' U L2 F R B U' L2 F' B2 R2 D2 L' D2 L F2 B2 L2 F2 L F' U R

(U' F U) // 122
(R D' R2) // 222
(F') B2 L U2 L2 U F' B' L' B * // 4E3C
L2 D2 L2 D2 L2 D2 // L3C

* B R' B' L' B R B' L

Very bad scramble, thus I'm happy I had the best result on this one. Only thing I could have done better : the 4E could have been inserted, resulting in a 5 moves insertion and 27 Moves in total.

Solution // B2 L U2 L2 U F' B' L' B2 R' B' L' B R B' L' D2 L2 D2 L2 D2 F R2 D R' U' F' U - 28 Moves

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

Spoiler

I // F' U R D' L D2 B2 D2 F D R' D R2 B L2 U2 D2 B2 L2 U2 F D2 R2 F' U R

U' L D // 122
(U' L2 U F U' R2) // PF2L-1
(U' B L' B' L U R') // L4C

Skel // U' L + D R U' L' B L B' U R2 U * F' U' L2 U - 16
* U2 F' D2 F U2 F' D2 F
+ L' D L U' L' D' L U

Optimal is 26, I don't know why I missed since it's with the same first commutator as I did. Too bad, it would have been tied 3rd place with that ...

Solution // U' D L U' L' D' L U D R U' L' B L B' U R2 U' F' D2 F U2 F' D2 U' L2 U - 27 Moves

 

[mycube]

Quite frustrating results for me last weekend at Cubelonia 2016:

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

Spoiler: 25 Moves

Same as Reto (Bubtore), so see his solution for the first scramble above my post (fun fact: 4 people found the same solution). Maybe I have different insertions, but I can't remember.
I have nearly the same thoughts, hoped for way better insertions, so I spent a lot of time on this skeleton.

2 R' U' F L' F2 L2 B2 F2 L' D2 L D2 R2 B2 F L2 U B' R' F' L2 U' B R' U' F

Spoiler: DNF(28 Moves)

L' U R2 F B2 R2 B2 F' D R' - 223
D2 L' F L' F' - F2L-1
D' B D2 B' D2 L' D2 L D L' D' L D' - Finish

the marked L (next-to-last move) was a L' in my solution I was in a hurry in the last minutes, corrected another mistake and did not notice this one.. Actually what's really bad about this that I already had a 29 on my sheet but crossed it out as I was sure that the 28 is correct.

looks also promising:
L' U' R2 D R'
L F D' L' D' L2 F D' L

3 R' U' F R2 D2 F' U2 L2 B2 D2 U2 L2 B' R2 D' R D' F' D2 B2 D2 L' D R' U' F

Spoiler: 23 Moves

linear LL-skip-solution:
R' F U R' - 122 + pairs
U' B U' B' L' B' U B' F - F2L-1
R U' B' R2 B R B' R' B U - Finish

Solution:
R' F U R' U' B U' B' L' B' U B' F R U' B' R2 B R B' R' B U - 23 Moves

After finding the 23 on the last scramble I was really frustrated, this would have been a 25.33 (or 25.66 with the 29) mean which would have been pb and first place at the competition. Well, again a reason why FMC sucks

 

[AlphaSheep]

This may be better suited to the OQOA regulations thread, but we're already talking about FMC rules so...

I can't remember reading anything about how fast FMC scrambles must be checked. Would it be permissible to just check for podium, then check the rest of the solutions after the fact?

The regulations don't cover checking of results. It's really part of the result submission process that the delegate does. Results in general need to be checked before the delegate submits the results after the comp, but with FMC, ideally the competitor needs to be available to explain the moves, if necessary...

With the relatively high rate of DNFs that is possible in FMC, I think it's best to do at least a preliminary check before the results go on cubecomps.

What you could do is get as many trusted competitors as possible to help do a quick check of the solutions, with the delegate overseeing the process. It should only take 5 minutes, of course playing special attention to the podiums. Then after the comp while checking the scorecards from the other events, you do a more thorough check of all of the solutions.

 

[biscuit]

The regulations don't cover checking of results. It's really part of the result submission process that the delegate does. Results in general need to be checked before the delegate submits the results after the comp, but with FMC, ideally the competitor needs to be available to explain the moves, if necessary...

With the relatively high rate of DNFs that is possible in FMC, I think it's best to do at least a preliminary check before the results go on cubecomps.

What you could do is get as many trusted competitors as possible to help do a quick check of the solutions, with the delegate overseeing the process. It should only take 5 minutes, of course playing special attention to the podiums. Then after the comp while checking the scorecards from the other events, you do a more thorough check of all of the solutions.

Thanks! I ask because I'm planning to have one attempt at the very end (after awards and most of cleanup) and we'd be trying to get out pretty fast.

 

[AlphaSheep]

Thanks! I ask because I'm planning to have one attempt at the very end (after awards and most of cleanup) and we'd be trying to get out pretty fast.

Is a great idea. Definitely do it. We did at one of our comps once, and even checked the last attempt outside in the parking afterwards because we had to leave the venue. I only entered the results on cubecomps when I got home a couple hours later. It's also great because everyone not competing left so it was really quiet and peaceful.

 

[biscuit]

Is a great idea. Definitely do it. We did at one of our comps once, and even checked the last attempt outside in the parking afterwards because we had to leave the venue. I only entered the results on cubecomps when I got home a couple hours later. It's also great because everyone not competing left so it was really quiet and peaceful.

Yeah that was the idea. If we're on schedule, we should end by 6:20, but it'll probably be closer to 6:30. I said we'd be out by 7:00, and since we will already have cleaned up stackmats and all that, I think it's doable. Know I need to practice a little bit...

 

[wassekaran]

Solve this Scramble in FMC: U2 F2 U' F2 R' D R' U' L' U2 F'

 

[Hssandwich]

Solve this Scramble in FMC: U2 F2 U' F2 R' D R' U' L' U2 F'

F U2 L //roux block + 2x2x2
U // square
R D' R //reduce to domino
F2 U F2 U2 //finish