[Help Thread] FMC Discussion

[angham]

Can anyone tell me what 'NISS' actually means?

It stands for normal-inverse scramble switch. It is where you switch to the inverse of the scramble ie. R U B becomes B' U' R' because it may have better options available eg. easier 2x2x2 block. Then you just invert your solution for the inverted scramble and it will solve the original scramble. You can also do this part way through a solve doing the inverse of the moves you already did before the inverse scramble.
see this for an example
http://www.speedsolving.com/forum/showthread.php?13599-The-FMC-thread&p=258791&viewfull=1#post258791

Also, I am struggling to understand exactly what a premove is

A premove is a move you do before the scramble and then add on to the end of the solution to make the solution easier
For example consider the scramble D L2 B2 D' L2 F2 D2 F2 D' L2 U R' U' R2 B' L2 D' F U F R
If you do the moves L' U' L U2 there is a nice 2x2x2 block at the back, however the colours do not match up. If the white side were to be completely solved, a U2 would solve this block. So applying a U2 at the start of the scramble gives a 4 move 2x2x2 block, although you must put U2 at the end of your solve as well

One last thing, in fmc a rotation such as x counts as a move

 

[irontwig]

One last thing, in fmc a rotation such as x counts as a move

No it doesn't. But you should write your solution down without rotations, it makes e.g. insertions easier.

 

[angham]

No it doesn't. But you should write your solution down without rotations, it makes e.g. insertions easier.

oh, sorry, then i have been misinformed

 

[tseitsei]

what is a decent number of moves for 2x2x3 block and/or F2L-1?

I never know when I should look for something better and when to go with what I already have...

 

[brandbest1]

Premove + Scramble: F' L' B' L U D L' + D2 R' B2 D2 R U2 R B2 L2 U2 F2 D' B' D2 U' L D2 B2 F' D' (from the holiday competition)
2x2x3: B U R' U' R U R * U'

Insert at *: F2 D B D' F2 D B' D'

F2L: R D B R2 B' R2 F' R' F
OLL:F R2 F2 R' F R' F' R2 U F U'
PLL: D2 R S' R2 S R D2 R'
Undo Premoves: F' L' B' L U D L'

Solution: B U R' U' R U R F2 D B D' F2 D B' D' U' R D B R2 B' R2 F' R' F2 R2 F2 R' F R' F' R2 U F U' D2 R S' R2 S R D2 R' F' L' B' L U D L'

Yeah, this is my first time trying out insertions and premoves, what a way to start!

Help is appreciated.

Bump.

 

[kinch2002]

what is a decent number of moves for 2x2x3 block and/or F2L-1?

I never know when I should look for something better and when to go with what I already have...

Well that depends on how good you are at FMC. It's like asking what a good time for F2L is.
It also depends on what you have after the 2x2x3 (mostly the EO). If you're aiming for sub-30 (as I always do) then I certainly wouldn't move on until I had a 10 mover and usually would hope for 8/9. Again, that depends on the scramble, but it generally seems possible for me to get this whatever the scramble.

Spoiler

Premove + Scramble: F' L' B' L U D L' + D2 R' B2 D2 R U2 R B2 L2 U2 F2 D' B' D2 U' L D2 B2 F' D' (from the holiday competition)
2x2x3: B U R' U' R U R * U'

Insert at *: F2 D B D' F2 D B' D'

F2L: R D B R2 B' R2 F' R' F
OLL:F R2 F2 R' F R' F' R2 U F U'
PLL: D2 R S' R2 S R D2 R'
Undo Premoves: F' L' B' L U D L'

Solution: B U R' U' R U R F2 D B D' F2 D B' D' U' R D B R2 B' R2 F' R' F2 R2 F2 R' F R' F' R2 U F U' D2 R S' R2 S R D2 R' F' L' B' L U D L'

Yeah, this is my first time trying out insertions and premoves, what a way to start!

Help is appreciated.

OLL, PLL and an insertion is way too many steps. From what I can tell, the F2L is what you're solving 'wrong' to leave an insertion. This is an odd tactic, especially given that it isn't a very short 'F2L' (24 moves?). Try to solve to F2L and then force a 1LLL somehow (e.g. 3 corners left to insert/some sort of skip)

 

[Cubenovice]

Brandbest, try these starts and see how they work
F U' F U' R' U
or
F U' F U2 R' U2

2x2x3 in 7 moves incl premove R2

 

[brandbest1]

Brandbest, try these starts and see how they work
F U' F U' R' U
or
F U' F U2 R' U2

2x2x3 in 7 moves incl premove R2

lol i'm a blockbuilding cfop noob.

 

[Username]

Could someone give me some FMC tips?

 

[Cubenovice]

Could someone give me some FMC tips?

http://www.speedsolving.com/wiki/index.php/Fewest_Moves

Make sure to check the links at the bottom of the wiki page

 

[Username]

http://www.speedsolving.com/wiki/index.php/Fewest_Moves

Make sure to check the links at the bottom of the wiki page

Thanks! I'll check it out

Edit: I don't really understand the methods, i use Fridrich as speed and i don't know anything else.

 

[Cubenovice]

I don't really understand the methods, i use Fridrich as speed and i don't know anything else.

The good thing about FMC is that you don't need methods

Blockbuilding is intuitive, combined with some trial and error it is a powerful FMC tool.

Simple FMC approach:
Use blockbuilding to make a xxx-cross
Orient / Permute edges (intuitive)
Solve the remaining 3, 4 or 5 corners with commutators, preferably inserted into the earlier part of the solution.

So if there is anything to 'learn' then it's actually commutators.

 

[CubeRoots]

Decided to have a go at a timed FMC, using newly learned techniques of premoves, NISS, and solving all but 3 corners, instead of my usual methods.

scramble was from chatroom: R2 L2 F D F' U R' D U L2 R B' L B F R U' R2 F' L2 D' L' U' F L

Inverse, [Premove: F]: D
Normal, [Premove: D']: [F'] R B
Inverse, [Premove: B' R' F]: [D] R U L F U' L2
Normal, [Premove: L2 U F' L' U' R' D']: [F' R B] R' F' R F2 D' F' D2 R'
Inverse, [Premove: R D2 F D F2 R' F R B' R' F]: [D R U L F U' L2] D R D R' U R' D R' D' R' D R2 U' D

This gives skeleton for normal scramble of F' R B R' F' R F2 D' F' D2 R' D' U R2 D' R D R D' R U' R D' R' D' L2 U F' L' U' R' D' (32 moves)

Leaving 3 Corners to comm in somewhere. Ran out of time here and just did L F' L' B L F L' B'. I could go back and find best place etc but I can do that already, what I really need help with is this skeleton. I found the scramble pretty hard, and basically after the F2L-1 bit It all goes downhill . Anyone have some good resources/advice they know of to help me with getting to all but 3 corners solved? or have some advice on the solution I showed here. Disappointed with this solve, normally gett sub 35 without all these crazy techniques

 

[kinch2002]

Decided to have a go at a timed FMC, using newly learned techniques of premoves, NISS, and solving all but 3 corners, instead of my usual methods.

scramble was from chatroom: R2 L2 F D F' U R' D U L2 R B' L B F R U' R2 F' L2 D' L' U' F L

Inverse, [Premove: F]: D
Normal, [Premove: D']: [F'] R B
Inverse, [Premove: B' R' F]: [D] R U L F U' L2

At this point, you're right - the solve goes downhill. Either you didn't leave enough time to find a good skeleton finish, or you weren't patient enough, or you just aren't knowledgeable enough yet.
10 move 2x2x3 is fine to aim for 30 move solutions.
F2L can be done with R' F' R2 F R' D2 R'. Play around with that. Maybe try any LL ELL algs you know to force 3 corners. Afraid I'm not in the mood for FMC right now so I'm not going to finish it. Try doing EO during F2L. Pseudo F2Ls etc.

 

[Michael Womack]

Has anyone tried the iPod App called Cube Wizard? It's an app that can solve your 3x3 but it solves it in 21-23 moves and use a weird solution.

 

[CubeRoots]

Has anyone tried the iPod App called Cube Wizard? It's an app that can solve your 3x3 but it solves it in 21-23 moves and use a weird solution.

I jut downloaded it, actually an awesome app

 

[Michael Womack]

I jut downloaded it, actually an awesome app

Glad you liked it.

 

[CubeRoots]

Looking for some help (again ) this time it's with insertions. Scramble is the following:

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

solution as follows:

Normal (premoves: R2 D2 R2 F'), D' L U L2 F' D L R2... // F2L less one slot, and EO (essentially 12 moves)

... B' D B D B' D B D //all but 4 corners. (essentially 20 moves)

now this sucks as I have a corner orientation issue. How does one deal with this with insertions etc? atm all I can think of is to do a comm somewhere to cycle the three around and leave 2 corners misoriented, which I can solve mid solution too. Feels very inefficient. How would you finish?

 

[Cubenovice]

now this sucks as I have a corner orientation issue. How does one deal with this with insertions etc? atm all I can think of is to do a comm somewhere to cycle the three around and leave 2 corners misoriented, which I can solve mid solution too. Feels very inefficient. How would you finish?

It's not too bad, there's ony one corner twisted in place.

You solve this with 2 commutators:
1st: solve 1 corner and break the twisted corner free
2nd: the three remaining corners

In the 1st comm you can typically cancel a ton of moves as your 3rd piece in the cycle can by any of the two remaining corners and their orientation doesn't matter. So there are MANY possible insertions.

 

[kinch2002]

Let's say that A->B->C and D is twisted so C->A* (some other sticker on piece A)
At each move in the solution, you look for the following:
Is A->B interchangeable? Is B->C interchangeable, Is C->A* interchangeable?
Let's say that A->B is interchangeable.
You need to find a comm using that interchange where the third sticker involved is any sticker of D.
This freedom of the third sticker makes the 1st insertion better than a standard 3 corner insertion.
Once you've found the best possible 1st insertion, write down your solution with it, and resolve. You should see that you have 3 corners left to insert.

Here are the number I have in my head of how many moves I think each type of insertions will take. They are not in any way mathematically based - just my general feel for them.
3 corners left = 6 moves
2+2 cycle left (either with or without extra orientation) = 9-10 moves
3 cycle + twisted corner = 10-11 moves
5 cycle = 10-11 moves
2 twist = 9 moves
3 twist = Never tried it but optimal alg is 13 moves. 2 insertions using the same 3 pieces both times may give you 10-11 moves I think