[Help Thread] FMC Discussion

[okayama]

From FMC200, which was considered as a tough scramble by Mirek Goljan.

Scramble: F2 U2 D2 F' B D U' B F R B R' U L D2 L D U' L U2 L' F B2 D2 B' L2 F B2 L' F'
Solution: U2 F U' D' L B' D' B D' L U' L2 U' L D' L' U2 L D F U2 F U2 F' (24 htm)

Pre-scramble: F

2x2x2 block: U2 F U'
Siamese 2x2x2: D' L B' D' B D'
More 1x2x2: L U' L' U
Orient edges: U' L' U * L
All but 3 corners: F U2 F U2 F2
Pre-move correction: F

Insert at *: U2 L D' L' U2 L D L'

 

[Stini]

I have also tried scramble #200 a while ago, here's my almost linear try:

Solution: L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F2 B F' U F B U L U' L' B2 (25 HTM)

2x2x2: L' F B U2 B' D.
2x2x3: R U2 F2
F2L minus slot: B F' U F B'
Leave 3 corners: B2 U L U' L' B2 (1 move cancelled)

Insert D L2 D' R' D L2 D' R at the dot to cancel 2 moves.

 

[okayama]

I have also tried scramble #200 a while ago, here's my almost linear try:

Solution: L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F2 B F' U F B U L U' L' B2 (25 HTM)

2x2x2: L' F B U2 B' D.
2x2x3: R U2 F2
F2L minus slot: B F' U F B'
Leave 3 corners: B2 U L U' L' B2 (1 move cancelled)

Insert D L2 D' R' D L2 D' R at the dot to cancel 2 moves.

Quite elegant finish (the last step)! I'm impressed.

You beat all participants in FMC200 with an (almost) linear solve! I needed near 1-hour to get my solution above actually, after much trial and error.

 

[Stini]

I have also tried scramble #200 a while ago, here's my almost linear try:

Solution: L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F2 B F' U F B U L U' L' B2 (25 HTM)

2x2x2: L' F B U2 B' D.
2x2x3: R U2 F2
F2L minus slot: B F' U F B'
Leave 3 corners: B2 U L U' L' B2 (1 move cancelled)

Insert D L2 D' R' D L2 D' R at the dot to cancel 2 moves.

Quite elegant finish (the last step)! I'm impressed.

You beat all participants in FMC200 with an (almost) linear solve! I needed near 1-hour to get my solution above actually, after much trial and error.

I was just lucky that I didn't face any tricky situations. That last step is a common trick in Heise method that I use often to build a 1x2x2-block on top, check F2 conjugation here, but you can also use it as an optimal F2L-alg. Now it just happened to solve both.

 

[Swordsman Kirby]

Solution: L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F2 B F' U F B U L U' L' B2 (25 HTM)

I have a slight optimization for this.

L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F B U F B U L U' L' B2 (24HTM)

 

[Stini]

Solution: L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F2 B F' U F B U L U' L' B2 (25 HTM)

I have a slight optimization for this.

L' F B U2 B' D2 L2 D' R' D L2 D' R2 U2 F B U F B U L U' L' B2 (24HTM)

Haha, thanks for improving my solution

 

[undick]

Scramble from Biweekly Forum Competition#3 in Indonesia Cubing Forum (rubikku.ning.com)

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

Solution : B L' B2 L' B2 L2 D L B R B' D' R D' F D' B' D F' D2 R' U' B' U B R B' (27 moves)

2x2x3 : B L' B2 L' B2 L2 D L (8/8)
Finish F2L : B R B' D' R D2 * B' D' (8/16)
Leave 3 corner : R' U' B' U B R (6/22)
AUF : B' (1/23)

Insert at * : D F D' B' D F' D' B (4/27) cancel 4 moves

 

[Cielo]

I didn't realize there is fmc in the weekly competition here until I see this thread…
I participated in the last two competitions on fmc.mustcube.net and got a 33f and a 29f.

But I think it's lucky for me to get a sub-30 solution, because I don't have a good method to solve the last layer. Sometimes I have to use OLL + PLL.

 

[Ranzha]

Uhm, erm, I didn't know that there was an FMC thread.
So I'll just post a cool beans FMC solve I did....

Okay, I never do FMC, but I just got this awesome scramble and decided to FMC it.
Scramble: U F2 R2 D2 F2 D' R F2 U F2 U' R' F2 R2 D' U B.
Scramble with W/G U/F.

Solve:
2x2x2 block: (x2' y') R' L2 D2 -- 3 moves
2x3x3 block: (x') U F2 L F2 L' -- 5 moves
3rd pair: (z' y2) R U' R (y) L' U L -- 6 moves
4th pair + OLL: U2 (y' x) R2 U R U2 (x') U' F R2 U R' U R U2 R' -- 14 moves
PLL: (x) U2 r' U' r U2 l' U R' U' R2 D' -- 11 moves, optimal PLL.

39 moves, HTM. My best so far. ^_^.

EDIT: Added parentheses around rotations and movecounts after each step.

I just had a question: "Am I doin' it right?"
Am I on the right track to FMC?

 

[Stini]

Uhm, erm, I didn't know that there was an FMC thread.
So I'll just post a cool beans FMC solve I did....

Okay, I never do FMC, but I just got this awesome scramble and decided to FMC it.
Scramble: U F2 R2 D2 F2 D' R F2 U F2 U' R' F2 R2 D' U B.
Scramble with W/G U/F.

Solve:
2x2x2 block: (x2' y') R' L2 D2 -- 3 moves
2x3x3 block: (x') U F2 L F2 L' -- 5 moves
3rd pair: (z' y2) R U' R (y) L' U L -- 6 moves
4th pair + OLL: U2 (y' x) R2 U R U2 (x') U' F R2 U R' U R U2 R' -- 14 moves
PLL: (x) U2 r' U' r U2 l' U R' U' R2 D' -- 11 moves, optimal PLL.

39 moves, HTM. My best so far. ^_^.

EDIT: Added parentheses around rotations and movecounts after each step.

I just had a question: "Am I doin' it right?"
Am I on the right track to FMC?

Your block building seems to be quite efficient, so you are definitely on the right track.

OLL and PLL are seldom useful for FMC, so you should try to learn more advanced methods to finish your solve. I usually try to solve the cube intuitively until I have only 3 corners left, which can be solved with a short commutator and most of the time you can cancel some moves if you solve those corners somewhere in the middle of your solve with an insertion.

There are also other useful techniques such as pseudo blocks and pre-moves, which are really useful and you should try to learn to use those if you already haven't.

Also I find that using rotations makes it easier to make mistakes, especially during insertions, so I try to avoid using those. I guess it also looks neater.

Keep practicing!

 

[Stini]

Nothing special really, but I think this is my first sub-30 linear solve (I don't practice linear solving much, so I haven't got any lucky solves). I spent a bit less than 2 minutes for the whole solution.

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

Solution: R D' U2 R2 U2 B L B' R' B' F U2 F' B L' B' U' z R U' L' U u R2 u' R2 U2 L U' R2 (29 HTM)

Double x-cross: R D' U2 R2 U2 B L B' R' B'
Leave 3-corners: F U2 F' B L' B' U' (more obvious after L U)
Solve the corners: z R U' L' U u R2 u' R2 U2 L U' R2

The corner alg cancels two moves, so actually the solution is 27 moves, but I noticed that too late.

 

[undick]

I didn't realize there is fmc in the weekly competition here until I see this thread…
I participated in the last two competitions on fmc.mustcube.net and got a 33f and a 29f.

But I think it's lucky for me to get a sub-30 solution, because I don't have a good method to solve the last layer. Sometimes I have to use OLL + PLL.

I've got 28 on 1-hour llimit fmc.mustcube last week. My first sub-30 on fmc.mustcube. FMC is rock!!.

Still learning more officient blockbuilding and last layer.

 

[Ranzha]

Spoiler

Uhm, erm, I didn't know that there was an FMC thread.
So I'll just post a cool beans FMC solve I did....

Okay, I never do FMC, but I just got this awesome scramble and decided to FMC it.
Scramble: U F2 R2 D2 F2 D' R F2 U F2 U' R' F2 R2 D' U B.
Scramble with W/G U/F.

Solve:
2x2x2 block: (x2' y') R' L2 D2 -- 3 moves
2x3x3 block: (x') U F2 L F2 L' -- 5 moves
3rd pair: (z' y2) R U' R (y) L' U L -- 6 moves
4th pair + OLL: U2 (y' x) R2 U R U2 (x') U' F R2 U R' U R U2 R' -- 14 moves
PLL: (x) U2 r' U' r U2 l' U R' U' R2 D' -- 11 moves, optimal PLL.

39 moves, HTM. My best so far. ^_^.

EDIT: Added parentheses around rotations and movecounts after each step.

I just had a question: "Am I doin' it right?"
Am I on the right track to FMC?

Your block building seems to be quite efficient, so you are definitely on the right track.

OLL and PLL are seldom useful for FMC, so you should try to learn more advanced methods to finish your solve. I usually try to solve the cube intuitively until I have only 3 corners left, which can be solved with a short commutator and most of the time you can cancel some moves if you solve those corners somewhere in the middle of your solve with an insertion.

There are also other useful techniques such as pseudo blocks and pre-moves, which are really useful and you should try to learn to use those if you already haven't.

Also I find that using rotations makes it easier to make mistakes, especially during insertions, so I try to avoid using those. I guess it also looks neater.

Keep practicing!

Thanks for the advice! I kind of figured OLL/PLL is not an efficient way for FMC< and I didn't really know anything else.
I NEVER, EVER do block-building, so this trial was cool since I had a lot of breathing space.

I like using rotations, and I made sure I wrote rotations down and checked them for the correct notation (x from x', e.g.). I made sure that I checked orientation of the cube (say, U/F W/G to U/F R/B) if I had to switch a base colour, as it appears I did twice in my solve. Also, cancelling moves are koo too.

I'mma learn CLL/ELL, COLL, and perhaps MGLS this summer. Time will tell fo sho!

 

[okayama]

The last week's FMC ( fmc.mustcube.net ) was quite high-level! Almost all participants got sub-30...

Here is my first sub-30 solution in 1-hr limit (July 25, 2009). That was my 4th FMC.

Scramble: L2 R D2 R2 L2 F D U' B2 L2 B D' L' U' F2 U2 L B D' B R2 D' U R L'
Solution: U L' U L2 D' F' U F' z B2 R' B' R2 U' R U B' U B U L U L' U2 F' U B' U' F U2 (29 htm)

1x2x2 block: U L' U L2
2x2x2 block: D' F' U F'
2x2x3 block: (z) B2 R2
Orient edges: R B' R2 U' R
F2L minus 1 slot: U B'
Finish F2L: U B U B'
Solve edges: B L U L' U' B'
Corner OLL: B U' F' U B' U' F
AUF: U2

Nothing special, I was just lucky. In fact the next sub-30 appeared after 4 months (FMC277).

 

[undick]

I want to ask about premove.

How do you know with some premove you will get better blockbuilding moves? i mean not a premove for blockbuilding, but premove as a part of blockbuilding.

i really stuck.

 

[Matt S]

Blah made a nice post in this thread about the technique I think you're asking about.

http://www.speedsolving.com/forum/showthread.php?p=241389#post241389

 

[guusrs]

I want to ask about premove.

How do you know with some premove you will get better blockbuilding moves? i mean not a premove for blockbuilding, but premove as a part of blockbuilding.

i really stuck.

Hi,

Pre-moves, or sets of pre-moves can be found using NISS.
For example: If a move makes a pair on the inverse scramble, the inverse move as pre-scramble will generate a pair on the normal scramble. And vice versa.
The same holds for sequences of moves that create blocks.

So shortly: useful pre-moves for the normal scramble can be found with the inverse scramble!

Gus

 

[undick]

Hi,

Pre-moves, or sets of pre-moves can be found using NISS.
For example: If a move makes a pair on the inverse scramble, the inverse move as pre-scramble will generate a pair on the normal scramble. And vice versa.
The same holds for sequences of moves that create blocks.

So shortly: useful pre-moves for the normal scramble can be found with the inverse scramble!

Gus

Oh yeah, of course i'm already understand about that. But, in some of solution, i found that premove not generate a pair. Only change the colour of cubies at a place. i really didn't know about "how do you know the cubies in normal scramble, change to potential cubies in inverse scramble/after premove?".

 

[undick]

Blah made a nice post in this thread about the technique I think you're asking about.

http://www.speedsolving.com/forum/showthread.php?p=241389#post241389

Yeah. That quite nice technique. But, that wasnt' technique i ask.

Thanks Matt. ^_^

 

[Cride5]

Hi,

Pre-moves, or sets of pre-moves can be found using NISS.
For example: If a move makes a pair on the inverse scramble, the inverse move as pre-scramble will generate a pair on the normal scramble. And vice versa.
The same holds for sequences of moves that create blocks.

So shortly: useful pre-moves for the normal scramble can be found with the inverse scramble!

Gus

Oh yeah, of course i'm already understand about that. But, in some of solution, i found that premove not generate a pair. Only change the colour of cubies at a place. i really didn't know about "how do you know the cubies in normal scramble, change to potential cubies in inverse scramble/after premove?".

I sometimes use premoves when I have an F2L composed of pseudo blocks. For example, if you've completed a 2x2x3 and then you see a nice 1x2x2 which normally forms part of your last layer, you can just complete F2L with that block. If you re-scramble but apply the move you used to place that pseudo block then the block will now belong to the F2L.

Looking at this example from weekly comp #23:
Scramble: L D2 F' L2 B2 R2 D L2 R D2 L2 B' D' F R' F' D'
F2L-1: D' L' B D2 U2 R2 B2 D F2 L2 D' B' U' B

Gives this situation:


It's fine to just complete the LL from here, undoing the pseudo block at the end, but you can make your life easier by applying the premove D2 to get this F2L: