M Slice F2L (##15-16)

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’)


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.


13 Cubers / One Scramble

Once upon a time, this blog was something other than just a collection of my embedded Youtube videos. In fact, it was more like a repository of neat things related to cubing. Besides acting as an online chronicle of sorts, which is a function I still really dig, I want to steer the blog back to including other content.

This recent Cubing World video is a great excuse to do that. A follow up to last year’s Twelve Cubers, One Scramble video, this one features thirteen fast 3×3 solvers (two the current world record holders) each doing CFOP walk-through solves based on the same scramble:
L2 B' L2 B' D2 B' R2 D2 F2 R2 B' L B' U' R' D' B2 L2 U' B U2

This video is great. As I commented on it, the solves demonstrate really well that solving a cube is not just a robotic application of memorized steps — naysayers’ favorite criticism. No doubt there is a formulaic element of “see X and apply Y,” especially at the OLL and PLL stages. But the amount of variation in these walk-throughs showcases the high degree of analysis, problem solving, and creativity that go into a really good solve. And these are no lackeys. That some of the best cubers in the world each approached the same scramble differently is a testament to the deep complexity of the cube.

From Alexander Lau’s Roux and Phil Yu’s ZZ mind-benders to Justin Mallari’s impressive dexterity and finger tricks to Feliks’ and Mats’ always brilliant solves, the video is riddled with nuggets of awesome tricks and techniques to study. I can watch these over and over again…and have!