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Kit Clement

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OK! Thanks for the advice. I already know about NISS, but I will definitely try and look up how to do insertions.

Here's an example of a solution that uses both NISS/insertions for your scramble and 2x2x3 start:

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

U2 L2 B' U F' L U' //223 block (7/7)
(U F U' R) //F2L-1 (4/11)
(R F R2 D R D') //L3C (5/16)

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

*: U R2 U' L U R2 U' L'

Final solution: U2 L2 B' U F' U R2 U' L U R2 U2 D R D' R2 F' R2 U F' U' (21)

Moves done on the inverse scramble are in parentheses, the skeleton puts all them together back on the normal scramble only with 3 corners remaining. The insertion at (*) finishes those 3 corners while cancelling some moves.
 

White KB

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Here's an example of a solution that uses both NISS/insertions for your scramble and 2x2x3 start:

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

U2 L2 B' U F' L U' //223 block (7/7)
(U F U' R) //F2L-1 (4/11)
(R F R2 D R D') //L3C (5/16)

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

*: U R2 U' L U R2 U' L'

Final solution: U2 L2 B' U F' U R2 U' L U R2 U2 D R D' R2 F' R2 U F' U' (21)

Moves done on the inverse scramble are in parentheses, the skeleton puts all them together back on the normal scramble only with 3 corners remaining. The insertion at (*) finishes those 3 corners while cancelling some moves.
Thanks for the example! Also, I'm a huge fan of the Layer by Layer podcast, so extra thanks!
 

porkynator

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How about an exercise in finding EOs?

Try this scramble (#3 from the current German forum competition):
R' U' F L' B U2 L2 U F2 L2 F2 D' R2 B2 R D' R2 U2 R B U' B R' U' F

Can you find all 4-move EOs on F/B on normal scramble, no NISS?
U B2 R' B' L' U' L2 B2 L2 F2 D' F2 L2 D2 L2 B2 L2 B2 R U F2 D' U' B2 (24)

U B2 R' B' //EO (4/4)
L' (B2 U D F2 U' R) //DR (7/11)
U' L2 * U //Corner HTR (3/14)
B2 D2 [R2 F2 L2 F2 L2] //3e (7/21)

* = B2 L2 F2 D' F2 L2 B2 U' (8-4/25)

Replace [] with L2 B2 L2 B2 R2 to cancel one move with inverse.

I am happy with the result, but a bit disappointed that I have spent the whole hour trying out EOs on one axis and just on normal scramble.
Without NISS there were 8 of them:

U D L B - nothing good from here
U B2 R' B' - my final solution from here
L' R' U' B - I had like a DR in 14 from D2 R...
L' B2 D B - R simplifies for DR, but nothing good after that
B R' U B - I found this DR: D' L2 F2 R' D' R2 D, not very good
B U R' B' - I found this DR: L U F2 D2 R' U2 R, seems ok
B' L' D B - nothing good from here
B' D L' B - 3 nice pairs!

I spent about half an hour on the last EO, there was a lot to try:
1. B2 D (actually finish EO with B') then maybe R D B2 D' ?
2. L' D' L then I don't know B2 R2 D?
3. (D L U') this looks promising, possible continuation L2 U L' B2
4. (L U L) and then continue with DR with good corners on inverse?

Bonus question: can you find all EOs on FB in 4 moves, this time using also the inverse scramble and NISS?
Apart from the 8 EOs above there are 6 purely on inverse:
(R' F2 D2 F)
(R' B2 U2 F)
(F' D2 R' F)
(F' R' D2 F)
(B2 U R' F)
(B2 R' U2 F)

and another 2 with NISS:
U' B (R B)
B (R L B)
 

tseitsei

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Does anyone have a good tutorial/resource page to learn DR and HTR stuff from. I haven't cubed in years but decided to check this stuff out now.

Thanks

Edit: I can get EO + Orient 4 corners quite easily in about 6 moves but after that I take too many moves to get to DR. And I have pretty much no clue what is the best way to continue after I reach DR.
 
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Cuberstache

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Does anyone have a good tutorial/resource page to learn DR and HTR stuff from. I haven't cubed in years but decided to check this stuff out now.

Thanks

Edit: I can get EO + Orient 4 corners quite easily in about 6 moves but after that I take too many moves to get to DR. And I have pretty much no clue what is the best way to continue after I reach DR.
 

tseitsei

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Thanks! Looks great. I'll give it a closer look during the weekend
 

tseitsei

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The guide was great for DR I can now usually find several 10-12 move DRs for a scramble.

I have additional questions however:
The guide only briefly mentioned HTR so is there a more in depth stuff regarding that?

I understand that I can just do another DR on different axis (with some move restrictions) and can do that somewhat reasonably. However I often end up with "correct colors" (like only correct and opposite colored stickers on all sides) but corners are still not in HTR. So my question is:
Is there a human viable way of avoiding this or is it just "spam reductions until one eventually works"?
 

Jack314

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The guide was great for DR I can now usually find several 10-12 move DRs for a scramble.

I have additional questions however:
The guide only briefly mentioned HTR so is there a more in depth stuff regarding that?

I understand that I can just do another DR on different axis (with some move restrictions) and can do that somewhat reasonably. However I often end up with "correct colors" (like only correct and opposite colored stickers on all sides) but corners are still not in HTR. So my question is:
Is there a human viable way of avoiding this or is it just "spam reductions until one eventually works"?
The quarter turns in DR to HTR must have the same parity as DR to solved (DR to solved has the same parity as DR to solved corners which is an easier way to determine the parity). If it does not then the corners will not be in HTR.

These are the DR corner cases (minus symmetries and AUFs/ADFs):


F2 D R2 D and D2 R2 U' R2 U solve different HTR cases.
 

tseitsei

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The quarter turns in DR to HTR must have the same parity as DR to solved (DR to solved has the same parity as DR to solved corners which is an easier way to determine the parity). If it does not then the corners will not be in HTR.

These are the DR corner cases (minus symmetries and AUFs/ADFs):


F2 D R2 D and D2 R2 U' R2 U solve different HTR cases.
Hmm... So:
Lets say I find a "HTR" (not an actual HTR because of corner parity) that has even number of quarter turn moves after DR but corners end up not working.
If I go back and find a HTR with odd number of quarter turn moves then the corners will work? Did I understand it correctly?
 

Jack314

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Hmm... So:
Lets say I find a "HTR" (not an actual HTR because of corner parity) that has even number of quarter turn moves after DR but corners end up not working.
If I go back and find a HTR with odd number of quarter turn moves then the corners will work? Did I understand it correctly?
It must have an odd number of quarter turns for it possibly work. It could still not work though.
 

tseitsei

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It must have an odd number of quarter turns for it possibly work. It could still not work though.
Ok thanks.

Sorry to bother you further but is there a way to know in advance what will work and what will not work? Or do I just need to try different reductions until one works?

edit: also do we know what is the probability to get a working HTR if you use the correct number of quarter turns?
 
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Jack314

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Ok thanks.

Sorry to bother you further but is there a way to know in advance what will work and what will not work? Or do I just need to try different reductions until one works?

edit: also do we know what is the probability to get a working HTR if you use the correct number of quarter turns?
Corners are close to solved when the cube is in HTR. When doing DR to HTR the corners are brought closer to a state which is solved. Doing moves that bring the corners closer to solve is a good strategy to make your DR to HTR work.

F2 D R2 D and D2 R2 U' R2 U solve different HTR cases, if one of these do not give HTR try the other.

1/3 if you use the correct number of quarter turns.
 

tseitsei

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Corners are close to solved when the cube is in HTR. When doing DR to HTR the corners are brought closer to a state which is solved. Doing moves that bring the corners closer to solve is a good strategy to make your DR to HTR work.

F2 D R2 D and D2 R2 U' R2 U solve different HTR cases, if one of these do not give HTR try the other.

1/3 if you use the correct number of quarter turns.
Thanks a lot. I understand it better now and should be able to do full solves with it, Just need to learn more DR tricks to find efficient DRs and working HTRs quicker 👍
 

tseitsei

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First complete DR + HTR solve.
Scramble: R' U' F L2 D2 F2 U B2 D' U' B2 U' L' B' D2 U2 L F D F2 U F D R' U' F
Solution: F' U' L U2 B D2 F2 U' F' U F2 U' L2 B2 U2 R2 U' B2 U' B2 U2 F' B D2 F B' U2 B2 L2 (29)
F' U' L // 3/29 EO
U2 B // 5/29 DR - 4C2E
D2 F2 U' F' //9/29 DR
U F2 U' L2 B2 // 14/29 Setup for HTR trigger
U2 R2 U' B2 U' // 19/29 HTR
B2 U2 L2 * U2 B2 L2 // 25/29 AB3E
* = L2 F' B D2 F B' // 6-2=4 29/29

Quite lucky DR. Usually takes me about 11-12 moves.

DR to HTR is probably horribly inefficient but at least I was able to do it :D

I have no idea if what I did while in HTR is actually good or not but 10 moves doesn't seem that bad for me.

Edit: Big limitation for me right now seems to be that I'm very slow at finding stuff since I'm just learning the method so I won't have time to check that many different ideas to get lucky more.
Critique and/or tips are most welcome if someone wants to take a look at it.

Edit:
A very good solve (for my standards) during some Christmas Eve FMC!
Scramble: R' U' F L2 D R2 F2 D' L2 R2 D2 R2 U F' R' U F2 U' B2 U2 L U' F' R' U' F
Solution: D' B' U L D2 F2 D' F2 U B' U' F2 U B2 D B2 U D' B2 L2 B2 L2 B2 U2 (24)

D' B' U L // 4/24 DR - 4c2e
D2 F2 D' F2 // 8/24 making the DR "bars"
U B' // 10/24 DR
U' F2 U B2 U // 15/24 lucky HTR
R2 * L2 ^ U2 // 18/24 leaves 2e2e3e
* = R2 U' D B2 U D' // 6-4=2 20/24 leaves 2e2e
^= L2 B2 L2 B2 L2 B2 // 6-2=4 24/24

A very good solve overall. HTR felt very lucky but good solvers always get lucky on FMC
 
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tseitsei

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Just got an amazing 18 move solve!!
Scramble from active weekly competition (fmc-weekly.cubing.net) so don't look if you don't want to spoil it.
Scramble: R' U' F R U2 F' B' U2 R' B' U B2 D2 L2 F2 L F2 R B2 R2 F' U' R' U' F
Solve: F2 B2 D B2 R2 B2 L2 D2 B' U B2 D' U B2 R F2 L B' (18)
Explanation:
(B L' F2 R') //EO (4/18)
(B2 U' D B2 U' B) //DR (10/18)
F2 B2 D //HTR (13/18)
B2 R2 B2 L2 D2 //FINISH (18/18)

Can someone check if this is optimal? I don't have cube explorer installed right now.
 

cuberswoop

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Just got an amazing 18 move solve!!
Scramble from active weekly competition (fmc-weekly.cubing.net) so don't look if you don't want to spoil it.
Scramble: R' U' F R U2 F' B' U2 R' B' U B2 D2 L2 F2 L F2 R B2 R2 F' U' R' U' F
Solve: F2 B2 D B2 R2 B2 L2 D2 B' U B2 D' U B2 R F2 L B' (18)
Explanation:
(B L' F2 R') //EO (4/18)
(B2 U' D B2 U' B) //DR (10/18)
F2 B2 D //HTR (13/18)
B2 R2 B2 L2 D2 //FINISH (18/18)

Can someone check if this is optimal? I don't have cube explorer installed right now.
Got you homie. Give me a sec.

EDIT: Cube explorer is taking a long time.
 
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tseitsei

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where can i start learning FMC?

This alone has insane amounts of info and will keep you occupied for months probably.
Concepts like Edge orientation, block building, premoves, NISS, insertions etc. are all very important.


Once you get those "basics" down you probably want to learn Domino reduction too.
This
https://docs.google.com/document/d/11WEvViCZViK0vPjy_ujGI_9aSGnkGg04JpCFjyK0g9o/edit
is great for that.

After DR you want to learn Half Turn Reduction too which is basically just doing a DR on another axis with some limitations. However there are lots of tips and tricks but unfortunately I couldn't find a clear document about that topic while starting to learn it a month or so ago. I might write something about it myself after I have practised some more with it.
 
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