Message #3294

From: Thomas Lehéricy <thomas.lehericy78@orange.fr>
Subject: re: [MC4D] Re: Greetings
Date: Tue, 23 Feb 2016 17:21:58 +0100

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