Hi,
I have few questions regarding this topic and I'd like to explain some my thoughts about M2/R2.
Well, I was using typical-basic version of M2/R2 (with no improvements). My buffers are FD and FDR. Now, after reading this topic, I'm gonna improve my method, especially the ugly cases.
And, here is the question:
What is better: to learn all 24 cases for M-slice edges (what Freddy88 wrote here:
http://www.speedsolving.com/forum/s...ents-for-M2-R2&p=107654&viewfull=1#post107654 ), or learn only 2 of them (UF<->DB) + learn to avoid the UB sticker (what Haru has explained here:
http://www.speedsolving.com/forum/s...ents-for-M2-R2&p=184171&viewfull=1#post184171 ) ?
Basically the cons of the second version is that you have to combine with the edges during memorisation; and I wanna the memo is nice and clean, just no-thinking edge-by-edge as they are on the cube.
Corners before edges is somewhat unnatural. The side effect of solving the edges are only in the M slice. No corners are affected, so after solving the edges the corners are where they were in the beginning. This is not the case the other way around, as solving corners does affect edges. Though in the end that's just a problem in case of parity. If there's parity and you solve corners first, I think you can apply my parity fix after solving corners and then solve the edges, though you'd have to start edges not like usual but as if you had already solved one edge, i.e., with the edge solving side effect already in place.
I'm solving corners before edges (using my short memory), and my solution in case of parity is that after solving all corners i do R2 move (so that edges are on their places and FDR is swapped with BRU). After solving all edges I undo the R2 move and then I execute the M2R2 parity alg.
I'd like to mention other one thing I didn't see in the topic (and some ppl might not know that).
When there are some stupid edges, that means they are on their places but disoriented after scramle, you can avoid ugly cases of M-slice.
Instead of a ugly cycle: FD->UB->UF and then orienting FD and a stupid edge, you can do nice algs for BU and FU, then orient UB and the stupid edge.
An example:
Scramble: R2 B2 R2 U' L2 B F2 R B' D' L2 B' R' B
Normal, ugly solve:
(UB) - (U R’ U’ l U’ R U) M2 (U’ R’ U l’ U R U’) (thx for this great alg btw)
(UF) - M2’ D (UR2U’ M’ UR2U’ M) D’
orient DF and UR
Solve with the trick I've mentioned:
(BU) - M2
(FU) - M U2 M U2
orient UB and UR.
Interesting thread.
I don't like having to shoot to FU or RD to deal with bad targets. That actually requires thinking! Since I've been experimenting with a lettering scheme, I've found it natural in M2 to associate each letter, not each position, to an algorithm.
To make things easy, I'll use DF as the buffer in this post. I'll write (s) to represent the move in M2 that brings s, which can be any sticker in R/L layer, to UF, and (s)' for the inverse of (s). For example, (FR)=URU'. We can then handle the bad targets as follows:
(Next two stickers memorized: solution)
FU s: M2 (s) M (s)' M
s FU: M' (s) M' (s)' M2
BD s: M2 (s) M' (s)' M'
s BD M (s) M (s)' M2
For example, to do (DF BD FR), use the third line: M2 (FR) M' (FR)' M', or M2-URU'-M'-UR'U'-M'. This way, we don't have to think at all where to shoot. For example, BD=X and FR=G in my current lettering scheme, so that cycle is XG. I've already associated G with URU', so I just substitute that into (FR); I don't even think about where G actually is.
This combined with normal M2 methods allow us to solve two stickers, exactly one of which is in the M slice, very easily and actually pretty efficiently. I know, for example, that Stefan's way for FU is faster, but the difference is only an M2.
This idea rox! I'm gonna use it. Same as Macky, I have binded letters with adequate moves, and I less thinking is faster imo.
Sth regarding R2 for corners:
My algs for ugly-URB cases are:
U' L U L' U' L U R2 U' L' U L U' L' U
U' L' U L U' L' U R2 U' L U L' U' L U
I think they are pretty fast.
And do you know any other tricks to improve R2?
R2+ is nice and fast, but there is lot to learn though.
Cya
