Message #3298

From: Roice Nelson <>
Subject: Re: [MC4D] Re: Greetings
Date: Wed, 24 Feb 2016 11:17:04 -0600

These are great questions that I wish I had answers for. I will say that
even though I’m marked as the "first no macro solution" in the Hall of
Fame, I’ve always felt that not using that feature isn’t quite different
enough to warrant its own category. I think this just emphasizes what
you’re saying about computer assisted categories being fuzzy. Maybe a
useful approach here would be not to find the perfect categories right now,
but to figure a way for them to grow or change easily over time? You seem
to have laid out a good start in any case, with possible beginning
categories like:

  1. Human-only
  2. Computer-assisted (>50% human solve, some computer state space
  3. Human-assisted (>50% computer solve, I question whether there will be
    enough here since implementations would likely just jump to the next
    category like Don did.)
  4. Computer-only (humans are allowed to write the software)
  5. Singularity award (computers must write the software)

…with first and shortests for each. I’d vote to start with 1,2, and 4 I
think. We might want to consider putting 2/4 on a completely separate page.

On the topic of Go, I’ve had a background itch to learn for a long time,
and when I read the news about AlphaGo beating the European champion, I
finally decided it was time! I bought a board and some books, and have
been playing a lot the last few weeks. In fact, I was at my first meeting
with the Austin Go Club when your email came through last night. I had
high handicaps and was still getting crushed, but as expected I’m finding
the game extremely elegant, interesting, addictive, and fun - I can tell
this is a hobby that will stick. What are your predictions for the match
with Lee Se-dol? An Austin player I was talking to last night is betting
on the human. I’m rooting for AlphaGo, and am really looking forward to
following the drama!


On Tue, Feb 23, 2016 at 7:10 PM, Melinda Green
[4D_Cubing] <> wrote:

> Welcome Thomas indeed! There’s nothing like breaking one of our most
> cherished records for waking us from blissful slumber.
> I’m happy to create new solution categories though I’d like to make sure
> we have a rough idea how to determine where potential new methods will
> fall. Tools like reset, undo & redo are forms of computer assistance but
> they seemed gentle enough to not detract from an otherwise pure human
> solution. Macros OTOH required quite a bit more introspection and we ended
> up categorizing them as another valid human solution, though not directly
> comparable to no-macro solutions.
> How should we now consider more sophisticated computer assistance that
> goes beyond simple mechanistic aid into some forms of real thinking? I
> definitely want to create a "shortest computer solution" category. So far
> we’ve only had one by Don Hatch which produces solutions with around 1,500
> twists. Perhaps when we have a more efficient solution, we should create a
> "first" and "shortest" computer solution category pair like the others. I
> can also imagine a time in which a human only guides the broad strokes of
> an otherwise completely computer-driven solution. Would that be comparable
> to this new computer-assisted solution or should we then create a new
> "human-assisted" category in anticipation of our obsolescence? These are
> obviously more philosophical questions than practical ones but they might
> inform our immediate choices.
> I’m really hoping that someone will implement an efficient computer
> solution that can be integrated into MC4D and replace Don’s version which I
> sadly broke. It was nice having a true solution integrated, though 1,500
> twists turned out to be just a bit too tedious to watch. Something around
> 200 twists seems much more practical, plus it could be merged with the
> current "cheating" solution such that states involving less than that
> number of twists will simply reverse all those twists (ideally with some
> compression which I also broke), and solutions longer than that will use
> the full computer solution. In fact if we do this right, the real prize for
> the shortest computer solution could be its integration into MC4D!
> And speaking of human obsolescence, are any of you also Go players, and
> have you been following the news regarding the upcoming human vs. AI match?
> Go has been a very difficult game to program due to the roughly 200
> possible moves at every turn. Google’s AlphaGo AI recently crushed the
> European Go champion and next month will play against the legendary Lee
> Se-dol who has dominated the game for the last decade. That match has a
> $1,000,000 prize and could well be a watershed moment even bigger than when
> computers became the best chess players in 1996. The match begins on March
> 9th. Details here <>.
> Happy puzzling!
> -Melinda
> On 2/23/2016 9:35 AM, Roice Nelson [4D_Cubing] wrote:
> Welcome Thomas!
> My vote is that we mark this new solution as a first class record in a new
> category, "shortest computer assisted solve". I’ve considered trying to
> use the computer for attacks on the shortest competition in the past, and
> it’d be great if more folks were motivated to do this. With advances in
> this area we could, for example, come closer to intuiting what God’s Number
> for the 3^4 might be. We don’t even have a rough idea of what it is right
> now, upper OR lower bounds (as far as I know).
> Congrats on your impressive solve, and happy to have you posting here.
> Cheers,
> Roice
> On Tue, Feb 23, 2016 at 10:21 AM, Thomas Lehéricy
> [4D_Cubing] <> wrote:
>> Indeed. I looked at the wiki page after my first solves, but didn’t
>> understand everything and preferred to keep going with the method I was
>> designing - at this point using an analogue of CFOP was just the thing to
>> do, seing how intuitive it is when you know it well. Now that I read it
>> again it looks very clear, and it indeed looks the same as my own method up
>> to the last layer.
>> The last 3D face can be done in at most twice as many moves as one would
>> need for the 3D cube. To do that, one can simply "regrip" (rotate) the cube
>> so that the face one turns is always the same. Of course it can be
>> improved, for instance when using URU’R’: a single regrip in the middle and
>> all moves will cancel… So it’s only an upper bound. I don’t know of any
>> general method to optimize this step, although I would be extremely
>> interested.
>> The human Thitlethwaite is not particularly efficient at giving low-move
>> counts solutions, but still better than CFOP. I think you can hope for a
>> 40-50 move counts on average if you know all cases (which I don’t), without
>> optimizing it for too long. What is good is that each step is rather
>> intuitive, and it can be optimized and yields extremely good results:
>> Kociemba’s algorithm is derived from it.
>> Block-building methods seem the thing to do indeed. It seems to me that
>> Matthew Sheerin built his first two layers like this in his record. It is
>> not as optimized nor as flexible as Heise, and it would be indeed
>> interesting to see how well Heise translates into 4D - but that’s far
>> beyond my abilities right now.
>> Thank you for your answer!
>> Thomas