F2L

F2L #36 – S Slice Variant

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F2L 36
S-Slice Variant

R U S’ (R’ U R) S R’

setup: (R U’ R) U2 (F R’ F’ R) U2

Four months! It’s been four full months since my last video/post. Totally unlike me. Busy is an understatement. It’s finally time to come for air momentarily with a tutorial I’ve planned for a long time.

This one relates to F2L 36, a case that I’ve never liked. The standard alg — U2 (R' F R F') U2 (R U R') — isn’t terribly slow. Nor is it very smooth or fluid. (My older video on that version.) I’ve come to prefer a “tricked out” variant that comes by way of Teller West — and, no surprise, it’s based around the S slice.

Here’s an in-depth tutorial comparing the standard alg to the S slice variant, showing my finger-tricks (very different than Teller’s), and vindicating the standard alg for certain cases:

(cube: Maru CX-3, partially un-stickered)

Like most S-based algs, this one succeeds or fails on finding a fluid, effortless way to finger-trick the slice. I couldn’t manage it the way Teller does. But once I “made it my own” — my recurring advice to cubers of all levels — the alg came together quickly. I push the S’ right-to-left across the top using my index finger, which is naturally on the right side of that edge after the R U; I pull the S left-to-right across the top after the R’ U R lands my index finger to the left of the edge. Mechanically, it all makes sense. But timing is everything.

I’m fascinated by how this algorithm can be deconstructed into component parts to help explain it’s mechanics:

   R U
             S’
                   R’ U R
             S
   R’

The first “level” in blue is a standard corner insert. Sandwiched between is a series of self-reversing S slices at the next “level” in red, and between those a series of self-reversing R moves (with the critical U smack in the middle). Huh? Basically, it’s a corner insert. But, just before the final R’, the S’ knocks out an edge, the R’ U R brings around the replacement (previously stuck F2L edge). The S flips that edge while pairing it with the corner. When the corner finally inserts, it brings the edge with it. Pretty neat.

Once understood as an expansion of the simple R U R’ insert, it becomes obvious why the S version works only when the flipped edge is in its own slot. If the flipped edge is in another slot, you need to use another alg — as emphasized at the end of the video.

It was fun to spend time on this one. Busy I remain, but hopefully it won’t take another four months to pump out the next post.

M Slice F2L (##15-16)

Adventures in Cubing3 Comments

It was exactly three years ago this weekend that I solved a Rubik’s Cube for the first time. Escaping the craziness that can come with too much family over Thanksgiving weekend, I spent an hour in front of YouTube, scribbled some notes, turned on my webcam, and recorded this six-minute solve. I thought I was awesome.

Fast forward three years, and I’m not longer impressed by being able to solve cubes, even big ones. Speed is impressive (certainly the sub-10 folks blow my mind), but that’s never going to be me. Three years in, I’m still hovering at 30 seconds for a 3×3, and I’m actually ok with that. What impresses and intrigues me even further is deepening my knowledge; I’m always interested in learning new techniques and approaches (in my very limited spare time).

For a little while, now, I’ve been focussed on using the M slice to make easier and reduce rotations in certain “tough” F2L cases. These two — #15 and #16 — boiled to the top:

F2l #15

M U (Rw F’ Rw’) U’ M’

setup: M U (L F L’) U’ M’

equivalent: M U (L F’ L’) U’ M’
conventional: y’ (R’ U R U’) d’ (R U R’)

#16

M U’ (R’ F R) U M’

setup: M U’ (R’ F’ R) U M’


conventional: y’ (R U’ R’ U) d (R’ U’ R)

I’ve identified 8 other cases that are interesting contenders for M slice F2L. But some would be just as clunky as the conventional approaches. As Cyoubx very clearly articulates in this video, M slice (as part of forced rotationless) F2L taken to its extreme starts to approximate Roux — and bad Roux at that. I’m interested in exploring Roux more. But, for now, I think there are certain key F2L cases that can be converted to M and used in Fridrich/CFOP without veering into bad-Roux-land. While I continue to explore the others, I think these two work quite well.

S-Slice: F2L Edge Flip

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F2L 38
S-Slice Variant

R’ U S’ U’ (R B’ R’) S R B

For a while now, I’ve had a decent alg for flipping a placed but misoriented F2L edge: r (R U R’ U’) r’ U2 (R U R U’ R2). As I wrote earlier, this is a “purer” alternative — in that it does not affect the orientation of the U corners — to the standard algs of R’ U S’ U’ (R B’ R’) S R B and (R U R’ U’) (U’ R U2 R’) d (R’U’R). It’s regripless and fairly fast, but still a bit a clunky.

While learning an S-slice alternative to another F2L case (coming soon), it occurred to me that S may open up possibilities here, too. I reached out to TellerWest, king of tricked out algs, and we identified this as possibility:

R’ U S’ U’ (R B’ R’) S R B

As shown in this video, it works quite well:

S moves are not that easy nor natural for a lot of folks. Continue reading →

Excuses…Excuses — (0:39) Ao5 with a Cast

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Here’s a dirty little (not-so-)secret fact: I’m a mediocre cuber. Indeed, mediocrity is, in a sense, the raison d’être of this blog.

me·di·o·cre [mee-dee-oh-ker]
of only ordinary or moderate quality; neither good nor bad; barely adequate
     synonyms: undistinguished, commonplace, pedestrian, everyday; run-of-the-mill
     antonyms: extraordinary, superior, uncommon, incomparable

More accurately, I’d say that I’m a pretty good cuber, but a very mediocre speedsolver. My technique is decent. I know all PLLs and can execute them efficiently. I understand intuitive F2L very well, and have learned a lot of tricks for more complicated cases. And I’ve got about 60% of the OLLs under my belt. But when it comes to putting them all together into full solves, I’m just not that great. My cross stinks. My look-ahead is non-existent. And, under the pressure of the clock, I tend to confuse F2L cases and forget OLL cases. That’s why I average just under 30 seconds.

And that’s why I very rarely record full solves and, even more rarely, averages. Well, after my surgery and with this damn cast still on my arm (¡au voir mañana!), I thought I could record an average of 5 (Ao5) with a built-in excuse. And so I did. Here’s the video with a 39 second Ao5 (and with BIG apologies for so much of it being out of frame!):

(puzzle: Dayan Zhanchi w/ Cube Specialists fitted bright stickers; music: String Cheese Incident performing “Galactic > So What?” on 7.30.03)

Continue reading →

Still More Tough F2L (##15-18)

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This is the third installment in the tough/hard/weird/non-intuitive F2L series, with the first and second posts among the most popular on this site and my Youtube channel. These cases (#15-18) require splitting top-layer pairs before re-combining them — what the F2L wiki refers to as “splitting pairs by going over.” As with the cases in the other tutorials, having now spent some time with alternate algorithms, these seem less “tough” than just non-intuitive.

Following the format of the previous installments, here’s a video tutorial, followed by table contrasting my old (intuitive) approaches against the improved ones:

(music: Bassnectar, “Timestretch (West Coast Lo Fi Remix)”; cube: Maru CX3 w/ stock stickers)

Continue reading →