[Help Thread] FMC Discussion

[AvGalen]

Well, that's clearly false. twisted corners give the best cancelations as you have the most freedom during the first insertion. 2 twisted corners is surely the best "2 insertions" case. However, of course it is nicer in general to end up with 3 permuted corners instead of 3 twisted corners, as the former requires only one insertion.

In the end, it's always a matter your skeleton's length.

Why would you call that false? As soon as you leave one twisted corner (or edge) somewhere during your skeleton you will already need 2 insertions and about 12 moves to solve it. A piece that is in place but misoriented takes the most moves to solve. Superflip is one of the worst for this exact reason and even a single flipped cross-piece during a speedsolve is already bad (4 moves and not finger trick friendly)

 

[dbax0999]

a single flipped cross-piece during a speedsolve is already bad (4 moves and not finger trick friendly)

Off topic, but I always thought R' u R' u' was pretty good despite requiring a regrip.

 

[kinch2002]

Why would you call that false? As soon as you leave one twisted corner (or edge) somewhere during your skeleton you will already need 2 insertions and about 12 moves to solve it. A piece that is in place but misoriented takes the most moves to solve. Superflip is one of the worst for this exact reason and even a single flipped cross-piece during a speedsolve is already bad (4 moves and not finger trick friendly)

True if you solve linearly.
I would always expect <10 moves to double insert 2 twisted corners. It has so much freedom. I think I did it in 6 moves total once (6 4 move cancellations).
He was saying that saying twisted corners are a very bad case is false. If I don't have a 3-cycle left, 2 twisted corners is the next best case

 

[Sebastien]

Why would you call that false? As soon as you leave one twisted corner (or edge) somewhere during your skeleton you will already need 2 insertions and about 12 moves to solve it. A piece that is in place but misoriented takes the most moves to solve. Superflip is one of the worst for this exact reason and even a single flipped cross-piece during a speedsolve is already bad (4 moves and not finger trick friendly)

I call it false because the thought is rather false. While you are right that you need 2 insertions then, the skeletons are usually shorter.

Also 12 moves is way over the top. I'd rather say it is 8-9 moves for 2 twisted corners and 9-10 moves for 3 twisted corners or 4 corners with one of them twisted on average.

I also decided to call this "false" as I remember that I was afraid of twisted corners as well ~4 years ago when getting seriously into FMC and I first had to learn that this is wrong. I still remember that Erik got 4 twisted corners with 13 moves at a competition back in 2010 and we both were convinced that this is really bad lucky and not really suitable for insertions, while these days I would love working with that skeleton.

As another addition, you can barely "avoid" twisted corners, in the sense that doing something slightly different rsults in another skeleton that requires fewer insertions. Or even if, that generally means that you already performed one inserion without noticing it.

Edit: partially ninja'd by Dan.

 

[Erik]

Also 12 moves is way over the top. I'd rather say it is 8-9 moves for 2 twisted corners and 9-10 moves for 3 twisted corners or 4 corners with one of them twisted on average.

I also decided to call this "false" as I remember that I was afraid of twisted corners as well ~4 years ago when getting seriously into FMC and I first had to learn that this is wrong. I still remember that Erik got 4 twisted corners with 13 moves at a competition back in 2010 and we both were convinced that this is really bad lucky and not really suitable for insertions, while these days I would love working with that skeleton.

As another addition, you can barely "avoid" twisted corners, in the sense that doing something slightly different rsults in another skeleton that requires fewer insertions. Or even if, that generally means that you already performed one inserion without noticing it.

How would you go about solving 4 twisted corners though? Certainly not 3 insertions?? Even with good cancellations that is like 13-15 moves. (ok that would still get that specific attempt a 28 but still )

 

[TDM]

Sorry. I really should stop posting about things I don't know about.

 

[irontwig]

How would you go about solving 4 twisted corners though? Certainly not 3 insertions?? Even with good cancellations that is like 13-15 moves.

I would say more like 11 or 12.

 

[Sebastien]

How would you go about solving 4 twisted corners though? Certainly not 3 insertions?? Even with good cancellations that is like 13-15 moves. (ok that would still get that specific attempt a 28 but still )

Of course 3 insertions!

3 insertions aren't scarying me anymore these days. I would expect 11-12 moves just like Erik, basically 5-6 moves cancelation for the first insertion with immense freedom + ~9-10 moves for the L4C afterwards.

 

[porkynator]

I call it false because the thought is rather false. While you are right that you need 2 insertions then, the skeletons are usually shorter.

I have some doubt about this: what makes you think that skeletons that leave 2 twisted corners are shorter? Personal experience? I'd say they are even longer on average, since you need to solve one more piece!
anyway, I just consider 2 twisted corners as a bad L3C case (not really bad, but I expect 1-2 more moves), since it usually happens to me by chance when I try to leave 3 corners.

 

[AvGalen]

Of course 3 insertions!

3 insertions aren't scarying me anymore these days. I would expect 11-12 moves just like Erik, basically 5-6 moves cancelation for the first insertion with immense freedom + ~9-10 moves for the L4C afterwards.

Yes, it doesn't scare you anymore these days. Translation: For almost anyone else in the world this is a bad bad case.
"I would always expect <10 moves to double insert 2 twisted corners." ...and that is why I am saying it is a bad case. Having 3 mispermuted corners (or edges) would make you expect < 7 moves. Having 2 misoriented-in-place corners (or edges) would make you expect < 10 moves. Do you notice how 3 > 2 and 10 > 7 (less pieces, more moves)

 

[Laura O]

"I would always expect <10 moves to double insert 2 twisted corners." ...and that is why I am saying it is a bad case. Having 3 mispermuted corners (or edges) would make you expect < 7 moves. Having 2 misoriented-in-place corners (or edges) would make you expect < 10 moves. Do you notice how 3 > 2 and 10 > 7 (less pieces, more moves)

So what's the message?
If you have the choice between a 20 move skeleton with 2 twisted corners or a 20 move skeleton with 3 permuted corners the twisted corners would probably be a bad case. If the skeleton with 2 twisted corners was just 15 moves it wouldn't.

 

[Sebastien]

I have some doubt about this: what makes you think that skeletons that leave 2 twisted corners are shorter? Personal experience? I'd say they are even longer on average, since you need to solve one more piece!
anyway, I just consider 2 twisted corners as a bad L3C case (not really bad, but I expect 1-2 more moves), since it usually happens to me by chance when I try to leave 3 corners.

True, you're right about this.


--------------


Completely unrelated, I feel like sharing a very lucky L3C finish that I got yesterday within the German forum competition:

Scramble: L U D F L' U2 R2 B2 D' F U R2 B2 D' F2 D' B2 L2 B2 D2

On Inverse:
2x2x2+1x2x2: B * U' F2 L D L R2 U
EO: R' F'
L3C: R' D F2 D R F2

* = B U B' D2 B U' B' D2 (only one move cancelation unfortunately.)

Inverse solution: B2 U B' D2 B U' B' D2 U' F2 L D L R2 U R' F' R' D F2 D R F2

Solution: F2 R' D' F2 D' R F R U' R2 L' D' L' F2 U D2 B U B' D2 B U' B2

23 moves.

 

[kinch2002]

In conclusion:
If you intentionally solve everything but 3 corners, then 2 twisted corners is not a good case. You are more likely to get a 3-cycle case, which would be better.
If you are trying to solve a load of stuff, and hoping that 3 corners are left (I often end up solving all but 4 corners, and hope that I skip a corner) then 2 twisted corners is a decent case.
I would never define it as a 'very bad case'.

On another note, when I get 2 twisted corners I get that annoying thought of 'What if that one corner was twisted the correct way...everything would have solved' The probability 1/3 goes through my head too, even though I know that's wrong

 

[porkynator]

On the same topic, what about 5 corners that don't make a 5-cycle? I've always thought they're just as bad as 4 twisted corners; which is bad, unless I have a 15 move skeleton or so; and even in that case it probably won't be that cool, since shorter skeleton means fewer possible cancellations (see Sébastien's solve for example).

 

[TeddyKGB]

2 twisted corners isn't a bad case at all. On two separate occasions I've left 2 twisted corners and canceled 13 moves...

 

[EMI]

This whole "how good/bad are two/three twisted corners" discussion doesn't make much sense to me, as it obviously depends on the number of moves of the skeleton. Of course it's helpful to know how many moves a specific kind of insertion are taking you on average.

 

[Sebastien]

On the same topic, what about 5 corners that don't make a 5-cycle? I've always thought they're just as bad as 4 twisted corners; which is bad, unless I have a 15 move skeleton or so; and even in that case it probably won't be that cool, since shorter skeleton means fewer possible cancellations (see Sébastien's solve for example).

Well, what can I say here...

I would simply assume that both kind of skeletons are similar, as long as those 5 corners only requires 3 insertions (remember, 4 could be possible as well).

I have actually never worked with 4 twisted corners yet (I simply never found a short skeleton leaving those), but with 5 corners needing 3 insertion a couple of times. My 31 at EC14 was actually such a case in 15 moves, unfortunately having terrible cancelation. At Velbert Open 2013 though, another such 15 move skeleton resulted in a 26 move solution.

 

[Jimmy Liu]

4x4x4 fewest moves

Scramble: D' U' Fw' F L' Fw2 Uw F2 L2 Uw2 B' L' F' R' F2 D' L Uw2 B2 Fw F2 D' Fw2 F U2 L2 R2 Uw Fw2 D Rw2 R D Uw' U2 Rw U' L B2 Fw2

B2 Uw B' Uw2 R2 Uw' - two centers (3)【6】《6》
D' L' U R' Bw2 L Bw' - two centers (2)【7】《13》
Dw2 R2 Dw2 - all centers (2)【3】《16》
-------------------------------------------------
B' U2 B2 U' Bw - three pairs (1)【5】《21》
L' B L D' B D F R F' R' L' F L F' Fw' - three pairs (1)【15】《36》
U2 Lw' U L' U' Lw - all pairs (2)【6】《42》
-------------------------------------------------
Lw U2 Lw B2 Lw B2 Lw' B2 Rw B2 Lw' B2 Lw B2 Lw' B2 Lw' - OLL parity (8)【16】《58》
-------------------------------------------------
R2 D' F D2 F - 2x2x2 block
B2 D2 R2 D R' - another 2x2x2 block
B' L B L' B R B' R' - F2L
L B2 L' - F2L
R' B' U' B U R -OLL
R B R' U2 F' L B' L' B L' F U2 B (0)【39】《97》

 

[Prakhar]

There is no group specially dedicated to FMC for FMCers around the world, so I created this group. The group is new and will take time. FMC enthusiasts are welcome.
https://www.facebook.com/groups/1422080808012720/

 

[Kit Clement]

Finally, they accepted my application to club 31. What happens after the scramble switch is particularly ridiculous.

Done at Indiana 2014.

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

On inverse:
D U R2 L F' //2x2x2 (5/5)
D2 B2 D2 B2 //2x2x3 (4/9)
F' R' F2 D F' D2 //F2L-1 (6/15)

Switch to Normal:
D' R2 D //F2L (3/18)
F D R D' R' F' R2 //lol (7/25)

Skeleton:
D' R2 D F D R @ D' R' F' R2 D2 F D' F2 R F B2 D2 B2 D2 F L' R2 U' D'
@: B D' F' D B' D' F D (2 moves cancelled)
Final solution: D' R2 D F D R B D' F' D B' D' F R' F' R2 D2 F D' F2 R F B2 D2 B2 D2 F L' R2 U' D' (31)