[Help Thread] FMC Discussion

[tseitsei]

Or, if you're lucky enough, you might be able to finish with a pair 3-cycle

Yep. Or g perm but those are really rare exceptions I think

 

[APdRF]

Wow, so many possibilities I know what insertions are and know how to do pure conmutators, but I have problems finding cancellations and sometimes I have to do several attempts to write it down correctly Lack of practise I guess

@EMI, I'm gonna give a look at your solve right now.

Thank you all for the feedback!

 

[JustinTimeCuber]

can someone explain the FMC terminology? i confuzzled

 

[APdRF]

can someone explain the FMC terminology? i confuzzled

If you write the terminology you are confused with it will be easier to help

 

[JustinTimeCuber]

If you write the terminology you are confused with it will be easier to help

insertions, skeletons, niss, and how they work

 

[TDM]

insertions, skeletons, niss, and how they work

Skeleton: a sequence of moves that almost solves the cube, but leaves a few pieces (e.g. all but 3/5 corners is common)
Insertion: you insert a commutator into a skeleton to solve those pieces. You try to cancel as many moves as you can.
NISS: a method. More info here.

 

[KevinG]

Can someone explain to me how to find and use comms for edges?

 

[Joey VOV]

Here's how i do it, if it helps. At the end of this post is your solution in this notation.
Basically, I still imagine some moves to be on the "left side" of the scramble, and some on the right.
To differenciate, I put the moves on the left side / inverse scramble in brackets.
Let's ignore premoves for now, because they are only confusing. ^^
So if my 2x2x3 start works like this: (This is how I would post it in this thread, for example)

normal: R U R2
switch to inverse: B' L2 B'
switch to normal: D F D F
switch to inverse: R2

, I would actually write it down on my sheet like this:

R U R2 (B' L2 B') D F D F (R2)

The moves in brackets are the *inverted* premoves, so they are the moves I actually do on the inverse.
Note how this notation represents exactly the order in which you found the moves!
Now, if this is your current solution start, and, say, you now want to continue on the normal scramble, your premoves are the *inverted* moves in brackets, starting from the left.
So in this case your premoves would be
R2 B L2 B
Then the normal scramble has to be performed. Then you perform the "normal" moves, without inverting them, in the order you wrote them down:
R U R2 D F D F.
If, instead, you want to continue on the inverse scramble, you have to use the inverse of what I just described. So you start with the *inverted* non-bracketed moves from the right:
F' D' F' D' R2 U' R'
Then you perform the inverse scramble. Then then the moves in brackets, not inverted, and starting from the left:
B' L2 B' R2

This might seem complicated at first. But the nice thing is it is very easy to write down. To add some moves on the normal, just write them at the right hand end without brackets. To add moves on the inverse, write them to the right hand end, too, but in brackets. No need to start in the middle of your sheet, or something like that.
Always remember that the moves in brackets are the inverted premoves for the normal scramble, and the moves without brackets are the inverted premoves for the inverse scramble.
It is also worth noting that, if you want to make your start more readible, you can rearrange the parts of the solution a bit, by grouping the normal and inverse moves - as long as the normal scramble moves stay in their order, and the inverse scramble moves stay in their order. So to rearrange the above 11 moves you could write
R U R2 D F D F (B' L2 B' R2)
which is equivalent.

Now, the next thing you can use are premoves (for pseudo-blocks). The easiest thing to do is switching and treating the premove as moves like all the other moves. (With a bit of experience, this won't be necessary.)
But don't get confused by the order of premoves and moves on the inverted scamble. In my above example, the "last" move to create a 2x2x3 is a bracketed (R2). So after the first ten moves there will remain a pseudo-2x2x3 on the normal scramble, and a 2x2x3 with a missing move on the inverse scramble. The easiest thing to do is to apply that missing move on the inverse scramble (adding another switch, basically).

Now, when your skeleton is finally ready (which is when you should write down all the normal and inverse moves as just moves on the normal), what you have to write down are
- first, the moves on the normal, in the order you wrote them down
- second, *the moves you would normally apply as premoves before the scramble*, so the moves in brackets starting from the right (inverted).

So if we imagine that our little example above creates a L3C-skeleton already, this skeleton would look like:
R U R2 D F D F | R2 B L2 B

I hope this helps. It takes a bit of practise, but once you get used to it, I think this is the easiest way to keep track of your solution.

/-----------------------

Here is your above solution in my (actually, porkinator's) notation:

Scramble: D' B2 D L2 D2 B2 U' F2 L2 U L2 R F' U R2 B' F D' R D L2
Your solution: F2 L2 F B D' (D B U' B' U D' F2) F' (U' F' U2 F U2 R2 U) U' (F R2 F' R2 F R' F') (R' U' R D R' U R D')
Solution written down correctly: F2 L2 F B D' F' U' | D R' U' R D' R' U R F R F' R2 F R2 F' U' R2 U2 F' U2 F U F2 D U' B U B' D'
(As you can see your premoves were inverted.)
Again, my advise would be to just do another switch to perform a premove.

Okay, I get it now thank you. It is just something I need to spend more time with, I am not as quick a learner as I think I am sometimes.

 

[Bubtore]

Basically the only good commutator for edges is R' L D2 R L F2, or from a different angle of course.

 

[ryanj92]

insertions, skeletons, niss, and how they work

become enlightened

 

[Julian]

Basically the only good commutator for edges is R' L D2 R L F2, or from a different angle of course.

Disagree I think 6, 7, 8, 9, and 10-movers are all worth using. Less often than corners, of course.

 

[Kit Clement]

Basically the only good commutator for edges is R' L D2 R L F2, or from a different angle of course.

Even if you don't believe in anything more than 6 moves, what's wrong with R U2 R' L F2 L'?

 

[CyanSandwich]

Honestly though, I got a 23 using two edge commutators, one of which was 10 moves. My PB being 34.

Scramble: B2 F2 R2 U2 R2 U B2 D2 B2 U L2 B' L F' R' D2 R B2 R' F2
...
Skeleton: L' R2 B F' U' (+) (*) R2 L' B2 L' B' L' B D

Insert at (+): U2 S U2 S'
Insert at (*): S R B' R' S' R B R'
6 moves cancelled total.

Solution: L' R2 B F' U Fw F' U2 R B' R' Fw' F R B R L' B2 L' B' L' B D (23)

So it's worth a shot. But I didn't search any further, so there could have been better insertions.

 

[Bubtore]

Even if you don't believe in anything more than 6 moves, what's wrong with R U2 R' L F2 L'?

oh true ! I'm using my M-slices too much ...

Not associated to that, has anyone ever experienced this here ?!

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

AB3C // D F R’ B2 R F’ R’ B = F D’ L2 B R2 B’ + D2 R D F’ L D’ L’ D’ F2 D F’ D2
= B R’ B’ L2 B R B’ L2
+ B R’ B’ L2 B R B’ L2

 

[G2013]

Honestly though, I got a 23 using two edge commutators, one of which was 10 moves. My PB being 34.

So it's worth a shot. But I didn't search any further, so there could have been better insertions.

Actually not, I checked with IF and you did optimal insertions

 

[porkynator]

About edge commutators: don't forget the 8-movers!

R2 B2 L2 U B2 R2 F2 D

and

R2 B2 L2 U L2 B2 R2 D

and inverses etc...

and the cyclyc-shift variations:

R2 B2 L2 U B2 R2 F2 D
B2 L2 U B2 R2 F2 D R2
L2 U B2 R2 F2 D R2 B2

solve exactly the same case!

 

[G2013]

About edge commutators: don't forget the 8-movers!

R2 B2 L2 U B2 R2 F2 D

and

R2 B2 L2 U L2 B2 R2 D

and inverses etc...

and the cyclyc-shift variations:

R2 B2 L2 U B2 R2 F2 D
B2 L2 U B2 R2 F2 D R2
L2 U B2 R2 F2 D R2 B2

solve exactly the same case!

How are those comms formed? I can't find a structure

 

[porkynator]

How are those comms formed? I can't find a structure

Honestly, I have no idea. I promised to myself I would study them in detail sooner or later, but for now I just use them without knowing how they work.

 

[not_kevin]

Honestly, I have no idea. I promised to myself I would study them in detail sooner or later, but for now I just use them without knowing how they work.

I confess I still don't fully understand them, in the sense that I fully understand corner comms and the other common edge comms, but I was able to read through this description Ranzha linked me to on the Facebook group and make sense of how it roughly works:

https://www.speedsolving.com/forum/...rithms)-work&p=1054905&viewfull=1#post1054905

 

[Meneghetti]

Official 24 single @ SESC Santos 2015! And 29.67 mo3 (24, 29, 36)

Scramble: B U2 B D2 R2 U2 B L2 B D2 U B' U L D L' F2 L' D2 B L'

Spoiler

U' R' U2 L B R2 // 2x2x2
U' F2 U F // 2x2x3
F' L2 F2 U' F' // EO
L U2 L' // F2L-1
L U2 L2 U' L2 U' L2 U2 L U // AB3C

Found this in the first 3 minutes lol

Skeleton: U' R' U2 L B R2 U' F2 U L2 F2 U' * F' L' U' L2 U' L2 U2 L U
insert at *: U F' D F U' F' D' F (5 cancellations)

Solution: U' R' U2 L B R2 U' F2 U L2 F D F U' F' D' L' U' L2 U' L2 U2 L U (24 OBTM)