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ZZF2L 'Openslotting' Algorithms

Cride5

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When solving ZZF2L I find myself inserting C+E pairs into 'open' slots almost as often as closed ones. Although it can improve efficiency, the main reason I do it is for lookahead. Where an initial 1x2x2 belongs in a front slot, I normally place it into the back to fill up the hidden edge positions (BL and BR).

Although I've been doing this for quite a while, I've never actually looked at the best algs for solving into an open slot. While some of the cases are best solved by closing the slot and executing the normal alg, many cases can be more efficiently solved by an alg optimised for this situation.

All cases are presented below for completeness, however some of them can probably be ignored. Some are based on just closing the slot, while others can be easily worked out through intuition.


Basic Cases


(U) L' U R U' L . . (5f)
(U) R U2 R' U' R . . (5f)


(U) R' U L U' R2 U L' . . (7f)
(U) R2 D R' U2 R D' R' . . (7f)
(U') R U2 R' U' R U R' U' R . . (9f)


R2 U2 R2 U' R2 U' R' . . (7f)


R U R' U' R U' R' U' R . . (9f)
R U2 R' U R U R' U' R . . (9f)
R B2 U L U' L' B2 . . (7f)


(U') R U2 R' U R U' R' U R . . (9f)
(U) R' U2 R2 U R2 U R2 . . (7f)


(U') R U' R' U R U' R' U R . . (9f)
R U R' U2 R U2 R' U R . . (9f)
R B2 U2 R B2 R' U2 B2 . . (8f)



Corner Trapped


R U2 R' U R . . (5f)


R U' R' U' R . . (5f)


R U L' U R' U' L R . . (8f)
L R U' R' U L' U R . . (8f)
R U R' U' R U' R' U R . . (9f)



Edge Trapped


R U R' U' R . .(5f)


R U' R' U R . . (5f)


R U R' U R U' R' U' R . . (9f)
(U') L' U2 L F2 R' F2 R2 . . (7f)
(U') L' U2 R U2 R' U2 L R . . (8f)



Both Trapped


R' U2 R' U R U' R U2 R2 . . (9f)
R2 U2 R U' R U R' U2 R' . . (9f)
F2 U' F2 R' D R' D' R' . . (8f)
R' D' R' D R' B2 U' B2 . . (8f)


R U' R U2 R2 U' R2 U' R' . . (9f)
R' U' R2 U' R2 U2 R U' R . . (9f)


R U R2 U2 R U R' U R2 . . (9f)
R2 U R' U R U2 R2 U R . . (9f)



Connected Cases


R U' R' U' L' U R U' L . . (9f)
R U R' U2 R U' R' U' R . . (9f)
F R B R' F' R B' . . (7f)
F' R B R' F R B' . . (7f)


(U') R U R' U' R U R' U' R . . (9f)
R' U' R2 U' R2 U2 R2 . . (7f)


R U' R' U2 R U' R' U R . . (9f)
(U) R' U' R U' R' U2 R2 . . (7f)


(U) R' U2 R U R' U R2 . . (7f)


R B2 L U L' U' B2 (7f)
(U) L' U2 L U L' U L R . . (8f)
R U R' U' R U R' U2 R . . (9f)
(U2) R U R' U2 R U R' U' R . . (9f)
 
Last edited:

StachuK1992

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I saw this thread last night, and was seriously sad when I saw now that it didn't have more posts!

This is great stuff (apart from the first 3, which are *really* intuitive :p)

Already they've been helping me....and distracting me from other puzzles. heehee

Great job,
statue
 

Cride5

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2009RIDE01

Matt S

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May 24, 2010
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Great work as usual Cride.

For almost all of the cases, the intuitive solution is the best, which is nice although a bit boring. I'm glad I'm not being enticed into trying short but ugly algs, since using F and B doesn't appear to save more than two turns in any case.

On a side note, I love to leave an open slot when the opposite side is still completely unsolved, because you have total freedom to make the pair.
 

Cride5

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Yup, having a slot open when you have a whole side free is an ideal situation, because the pair can be built quite efficiently, and then inserted very efficiently.

During my solves I don't like to enforce a specific block order, because it may be difficult to find specific pieces, but I find that the blockbuild is usually more efficient if I can finish a whole side before moving onto the next 1x2x2. The best situation is to be able to build the whole LH side first, building the blocks with R/U moves, then moving onto the RH side. Completing a whole side first means that 'algs' are only really necessary for the final C+E pair.
 
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