Improvements for M2/R2

[Stefan]

Try this scramble: U' R' U M' U' R U M

Usually I'd solve it like this:
U2 M' U2 M'
U R' U' M2 U R U'
x M' U M' U M' U2 M U M U M U2 x'

Of course the inverse of the scramble is the much better way, directly solving the next two edges with a simple short commutator. I intend to use this for the "ugly" targets FU and BD (or UF and DB, depends on your view), as they're just M or M' away from the buffer, turning these ugly cases into quite good ones.

The second improvement idea is to first solve the edges with M2 as usual, and in case of parity, immediately fix the parity (i.e. solve the M slice) together with solving the first corner. If the corner target is in the left slice, use an L turn as setup move and then one out of three algs (one for each possible corner orientation). If the corner target is in the right slice, one out of 7 or 9 algs (depends on whether you allow the UBR corner to be misoriented, like I do so far) and no setup turns.

 

[tim]

Thanks, Stefan for posting this. You showed me this commutator at the German Nationals, but unfortunately i was too tired to understand, what you are saying . And at home i couldn't figure out this easy commutator on my own...

 

[Stefan]

I just looked at Erik's page to see how people who solve the M slice edge with correct orientation might solve it:

F E RUR' E' RU'R' F' M2
x' RU'R'U M2 U'RUR' x

 

[masterofthebass]

I like putting the pieces in the correct orientation the first time. It's a little slower for me, but it saves me the time of flipping edges. My execution needs work (~30 secs), but o well, 2:30 isn't a horrible time.

 

[Joël]

Hey Stefan,

That is a good solution indeed. Especially for the so called ugly target. Basically, you just switch to an M'/M method temporarely .

It's funny how DF is your buffer, while mine if FD btw... I found out about this last weekend. I remember we had the same thing for the corners (with your old corner method and the pseudo Y perm), where I just LBU as buffer .

- Joël

 

[Marcell]

Wow, Stefan, both of these two ideas are great. Although the first one makes the memorisation a bit harder... But I guess once you get used to it, it gives a much nicer and faster solution for those "ugly" edges.

I hope you will develope these improvements and describe them on your website.

 

[Lucas Garron]

I just looked at Erik's page to see how people who solve the M slice edge with correct orientation might solve it:

F E RUR' E' RU'R' F' M2
x' RU'R'U M2 U'RUR' x

Was going to post this earlier...
Anyhow, I'm planning to use that, but on 4x4x4 I go for safety not efficiency, so for this I'd do:
(URU')M2'(UR'U')M(URU')M(UR'U')M2' (uRu')M2'(uR'u')
The first part is an intuitive swapping.
The second part is a nice 3-move setup I found for RB (I don't like lU'R'U). Mirror works for LB, and u'Lu & uRu' work just as well

I decided that orienting resolved through setup is useless. I will either switch EO to F2/B2 restriction or (more likely) use M2 with tricks. I'm practicing M2 now.
Looks like we'll have a BLD revolution before the next Worlds...

By the way, I did 7 solves before getting ready for my MIT interview on Monday. 2 DNF's, the rest averaged to 1:35 (best was a 1:21... )

 

[Joël]

I also found another small improvement that I'd like to mention. I found that I don't really like to shoot to BL (I use FD as buffer btw, not DF), because I have to do x' and 4 setup moves. However, I DO like shooting to BU. Suppose the next two targets are BL and RF. I can use a setup move B', than just solve the first target with M2:

[Setup] B'
[Shoot to BL] M2
[Shoot to RF] URU' M2 UR' U'
[Undo setup] B

This shows once again how close to a 3 cycle method M2 really is.

Btw, should I put 'shoot to BL' or 'shoot to BU'? hmmmz..

 

[Joël]

I was thinking about this other nasty case... Shooting from buffer (in my case FD) to BU, which involves flipping both the edges.

A possible way to deal with this is to setup the second next target at RD (or LD, and do a similar alg). Then do the algorithm:

y M' U M D M' U' M D' y'

This solves the next two targets.

 

[masterofthebass]

Stefan posted this in another M2 thread.

I still have one more to learn (stupid UB).

Maybe you like this one better:
(U R' U' l U' R U) M2 (U' R' U l' U R U')

It only solves UB but it does work pretty well. I like the idea of being able to do a 3-cycle though.

 

[Joël]

Stefan posted this in another M2 thread.

I still have one more to learn (stupid UB).

Maybe you like this one better:
(U R' U' l U' R U) M2 (U' R' U l' U R U')

It only solves UB but it does work pretty well. I like the idea of being able to do a 3-cycle though.

Yes, that is the one I use. The thing is though, it's 15 moves to solve 1 edge, whereas the suggestion I did solve 2 pieces in 8 moves, that's about 4 times more efficient .

 

[jerjero]

can M2 edges be combined with 3 cycle corner permutations?

 

[Marcell]

Of course. If parity occurs you can do M2 U2 M' U2 M and you'll have UB and UF swapped, so figuring out what pll to use is also very easy.

 

[AvGalen]

Yes, but fixing parity would be different.

Too late. Our coffee machine is slow

 

[masterofthebass]

You could also do U' F2 U M2 U' F2 U to switch UB and UR, which I do because I uses old Pochmann Corners (Y perm). I was never able to understand 3 cycle cornes, so my suggestion may be a little biased.

 

[jerjero]

how will u clean messed up orientations for M2? sometimes my UB, UF, DB AND DF are misoriented how should i know if its oriented.. because when i inspect the cube it is correctly oriented but after i finished the edge cycle those targets are misoriented how will i aid this up?

 

[Lucas Garron]

A while ago, I figured out a nice way to shoot FU and DB ( I never liked Erik's algs )

FU: D [M' , U R2 U'] D' M2'
DB: M2' D [U R2 U' , M'] D'

The best part: These work for r2 on 4x4x4 BLD!
[M => r]

Beats UR'U' r2 URU' r' UR'U' r' URU' r2 and so...

 

[philkt731]

A while ago, I figured out a nice way to shoot FU and DB ( I never liked Erik's algs )

FU: D [U R2 U' , M'] D' M2'
DB: M2' D [M' , U R2 U'] D'

The best part: These work for r2 on 4x4x4 BLD!
[M => r]

Beats UR'U' r2 URU' r' UR'U' r' URU' r2 and so...

sorry but what do the brackets and the comma mean...?

 

[philkt731]

Stefan posted this in another M2 thread.

I still have one more to learn (stupid UB).

Maybe you like this one better:
(U R' U' l U' R U) M2 (U' R' U l' U R U')

It only solves UB but it does work pretty well. I like the idea of being able to do a 3-cycle though.

Yes, that is the one I use. The thing is though, it's 15 moves to solve 1 edge, whereas the suggestion I did solve 2 pieces in 8 moves, that's about 4 times more efficient .

yes but that doesn't include setup moves, which are surprisinlgy (or not) short (averages to 1.65 setup moves per edge): 0 or 1 or 2 for all edges on R or L (if you include using LD as another buffer spot) by using S and R/L and then 3 or 4 moves for M layer edges. I love this idea although it would take me a while to get used to it

 

[Kenneth]

bla bla bla =)

Or: "I just realised I was wrong"