M2M Day 70: Wow, could I get luckier?
This post is part of Month to Master, a 12-month accelerated learning project. For January, my goal is to solve a Rubik’s Cube in under 20 seconds.
Today, I was trying to select which set of last layer algorithms to learn, when I stumbled on something amazing…
Two-Look OLL algorithms
As explained yesterday, 57 of the 78 Rubik’s Cube algorithms are used for the Orient Last Layer (OLL) step of the solve. Thus, I suspected that OLL would make up most of my algorithm learning effort.
However, surprisingly, after today, that’s no longer true:
This morning, I learned about something called Two-Look OLL, which basically means “If I’m willing to string together two algorithms back to back (instead of using just one algorithm), I only need to learn 10 OLL algorithms to cover all 57 OLL patterns”.
Here are those algorithms:
At the beginning of this month’s challenge (and as of this morning), I only knew a random assortment of 9 OLL algorithms that I picked up over the past many years of casual cubing.
I have no idea why I know the particular set of algorithms I do. I just do.
When I learned about “Two-Look OLL” this morning, the first thought I had was “I wonder how many of the 9 algs I know match the 10 Two-Look algs”. If I just linearly extrapolate the probability (which is perhaps combinatoricly naive), I would expect something like a 15% match.
However, unexpectedly, I already knew 70% of the two-look algs. Somehow, 7 out of the 9 algs I already knew perfectly matched 7 out of the 10 two-look algs.
And, on top of that, the three algs I didn’t know were only minor variations on others that I did. In fact, because these three algs were so similar to others (i.e. mirror images, one move apart…), I was able to learn all three new algs in ten minutes.
Normally, it would probably take a day to fully incorporate a new alg.
Thus, excitingly, as of today, I know all the OII algorithms I need for this month’s challenge (I’ll prove why two-look is sufficient below).
It feels oddly lucky how much overlap there was between the set of algorithms I knew and the set of algorithms I wanted to know, but I suspect there is some underlying reason that propelled me to learn these particular algorithms in the first place. I’m just not sure what that underlying reason is.
If you’re a speed cuber and have a reasonable guess, leave a comment. I’d love to know.
PLL algorithms
The remaining 21 algorithms (out of the 78) are used for the Permute Last Layer (PLL) step.
Unlike OLL, I’ve decided to learn all 21 this month.
I already know 7, so, over the next two weeks, I will learn one of the remaining 14 algs per day. This will afford me one full week, at the end of the month, where I can execute solves with full knowledge of all the relevant algorithms.
Will this work?
If I just learn Two-Look OLL and complete PLL, will I be able to execute sub-20-second solves? It looks like the answer is yes:
I reviewed the video of solves I made on Day 1 of this challenge, and extracted a few relevant statistics.
On average, I was using 3.2 OLL algorithms and 2 PLL algorithms to complete the five solves.
With two-look OLL and complete PLL, I’ll reduce the number of algs to 2 and 1 respectively. In other words, assuming time maps linearly to ‘number of algorithms’, I’ll be cutting my OLL time by 1/3 and my PLL time by 1/2.
In Solve 1 from the video, which is the most average solve (since I used 3 OLL and 2 PLL algs), it took me 6 seconds to solve OLL and 8 seconds to solve PLL.
Therefore, if I can reduce my times by the amounts above, I will theoretically be able to execute a 4-second OLL and a 4-second PLL, or, in total, an 8-second last layer.
In my post “I already need a new plan”, 8 seconds is exactly how much time I allocated myself for my 20-second solve:
- Cross: 2 seconds
- F2L: 10 seconds
- OLL: 2 seconds
- PLL: 6 seconds
I’m shifting some of my PLL time to OLL to compensate for two-look, but it seems like it will work out.
Tomorrow, I’ll start practicing the new algs and determine which training methods are optimal.
Read the next post. Read the previous post.
