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Rubik's 4x4x4 Story

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I got a Rubiks 4x4 in the mail on August 29 compliments of Discover Rewards. "It pays to Discover." At rst I just tried a couple familiar 3x3 algorithms on it only turning the outer edges. I decided if I only turned the outer edges, it behaved just like a 3x and could be solved just like a 3x. After awhile though I had to turn the middle. Let's let R mean what it does with the 3x3, that is, a turn of the Right face clockwise. Say r stands for the layer that is in from R. L is still left, but l is the layer that is in one from L. An li then would be a turn of the layer just inside the Left face counterclockwise. I did R li and made stripes around 4 of the sides. Then I turned the whole cube and did it again. And again and again. Many many times. It made some interesting patterns. Stripes, shies, checkerboards, and even got back to a solid color on one side at a time, although the edges were not all in the right places. Finally I just scrambled the whole cube until it was nice and mixed up. With the 3x3 I did not even attempt to solve it on my own without help. Well, I guess back in the 80s I did, until I found a couple books explaining how to do it. Then I put together a method of solution I liked from the stuff Id read and learned it. Eventually I quit playing with it and forgot how to solve it. When I got interested again this year I looked for solutions online immediately that I could learn. It has been fun learning not one, but several different ways to solve the 3x3. LBL (Layer By Layer) with and without a working corner, F2L (First 2 Layers) corner/edge pairs, Petrus, Corners First, and the Ultimate Solution. With the 4x4, I didnt want to look up a solution online before I spent some time trying to gure it out on my own. My rst observation was that the sides are not dened by immovable centers as they are on the 3x3. With the 4x4 there are 4 centerish pieces, but they can all separate and move around the cube just like the edges and corners. So my initial attempt was to start with the 4 center squares on each side. I got the whites pretty easily. Then opposite the whites I did the yellows. It was not quite as trivial since you have to think about the whites as you get the yellows. But it wasnt hard. Then I got the greens. It wasnt so bad, but then getting the blues opposite the greens took a little more thought. I think I could do it again. After getting those four sides that just left the red and orange sides. As it turned out I got the centers, but when I tried to get a solid layer some of the center pieces got misplaced. I ignored them and tried to proceed getting 2 full adjacent layers. I got within 1 edge piece. But then things just started getting worse. So I scrambled it up and started over. I decided to try starting with a 2x2x4 column. After attempting that for awhile I decided to instead go for a 3x3x3 block. Next, I decided to go for a 3x3x4 block and it didnt take too long to get it. The thing is, I didnt know if I was lucky on any of these steps, or if I was using a sound strategy for

solving it that will be just as easy every time. When I had 3 corners and 9 edge pieces to go I had a feeling I wouldnt get much farther. I hadnt used any algorithms. Id gotten this far by just moving pieces around 1 or 2 at a time. No help. No hints. But I was stuck. I used the 3x3 corner swap and orient sequences to get the remaining 3 corners. That left me just 9 edges away from getting it. After using another 3x3 edge cycle algorithm I knew I got 1 more edge. Just 8 edges away from solving it. I somehow got within 7, but then gave up and messed it up to try a new strategy. My rst strategy of August 30 was to go for all the edgepairs rst. I knew I could then get the corners using 3 cycles and if necessary twisting a pair in opposite directions. I gured I would ignore the centers so as not to have to think of too many things at once. Well, it worked... mostly. I guess if it only mostly worked, it didnt work. I ended up with one edgepair that needed to be ipped and two corners that needed to be swapped. I didnt know an easy solution for that. And, of course, the centers I ignored fell where they may, which was not into place. My next idea was to start with one edgepair and make a stripe all the way around the cube, then get the two remaining centers and go from there. I thought I was making progress, but kept scrambling one thing to get another. So I tried something else. I tried to solve the red, white, and blue sides so I would have what looked like a 3x3x3 on the other side. This strategy also ended close, but not solved. I was just about ready to start looking for solutions online, but fortunately our internet service was down. Before the day was over I decided to start with a 2x2x4 column, then expand it to 3x3x4, then 3x4x4, then see what the Last Layer looked like. I dont recall how far I got, but I didnt take any photos past the 2x2x4 if that is any indication. On August 31 I got internet access back and took a look at bits and pieces of websites, but I still didnt want to just learn someone elses solution. I wanted to get as far as I could on my own, and didnt feel that I had reached the limit yet. I read some introductory remarks here and there. One suggestion was to rst solve all the centers, then get all the edges together with their twins, then solve it like a 3x3x3. I tried. I got all the centers and was getting more comfortable with the strategies Id worked our for getting them. Then I worked out a system for joining edge pairs, but once I got 8 pairs I was stuck. My method left 4 edgepairs unmatched. So I just went on to getting the edgepairs into place, then xing the corners. I was left with only 5 edge pieces out of place. September 1 on the way to Jim and Rosanna Rutherfords wedding I got within 2 pieces of solving it. I still hadnt looked at any solutions online. I got the centers, then as many edgepairs as I could, then moved the edgepairs into place as well as possible,

then moved the corners into place and oriented them when needed. The big challenge was getting the centers and edgepairs. On the way home I got it down to 2 pieces again. September 2 I rediscovered a website that I thought would help me understand better some of the practical theory behind some of the algorithms that I had been using in solving the 3x3. I was hoping that understanding the math, the group theory, and how it relates to the 3x3 would enable me to discover on my own the sequences needed to nish solving the 4x4. http://grrroux.free.fr/begin/Begin.html Later on September 2 I wrote: Breakthrough! I nally gured out how to match all the edge pairs up. I think. Ive only done it this once, so Ill only know for sure if I can do it consistently. But since I only have one 4x4 and am not nished with the attempted solution I am explaining on this page, that little issue will have to wait. After matching up all the edge pairs I just moved them around the cube into their proper places. Some I just used simple twists and turns, then I used The Ultimate Solution Edge Series (4 twists) to get the rest. After that it was just a matter of putting all the corners in the right places and orienting them correctly. I thought I was home free. I was using The Ultimate Solution Corner Series (8 twists) to x the corners, and sometimes the twist two corners sequence from the Working Corner Solution that I know. A weird thing happened. I got down to two corners needing to be swapped. I know a sequence for swapping two corners (part of the LBL method I learned for the 3x3 at Jasmines site), but I knew it would mix up some edges. Not having much choice, I went for it hoping I would then be able to solve the edges. After getting the corners in the right places and orienting them correctly, I had another strange situation. Two edgepairs needed to be swapped. Like the 2-corner swap, this is an impossible situation on a 3x3. I gured Id play around with The Ultimate Solution Edge Series and see what I got. I ended up with an edge situation that can be xed with URURURURU. Thats what we call it, anyway. For those of you familiar with the notation, it isnt all clockwise! This is also part of the Working Corner Solution I learned from Mark Jeays site. After using URURURURU I had ve corners to x. Doing all the edge sequences moved some corners around. After doing what I can do with the cornersArgh! Two need to be swapped! I need to gure out how to swap 2 corners without affecting the appearance of the rest of the cube. Still on September 2 I nally got it. But I still hadnt gured out how to deal with the situation when I needed to swap two corners. I just gured Id try it again to see if I could get all the edgepairs again. It took me awhile but I gured it out. It was really fun guring things out without just following an on-

line guide. So how long did it take me to solve the 4x4? 4 days. It was time to get help. No, not that kind of help. Oh wait, back to the cube story. I found two places online that had helpful information about dealing with the swapped corners and ipped edges that show up at the end. One was by Chris Hardwick, and one by Philip Marshall. I liked parts of both, so incorporated the parts I liked into my personal solution. On September 4 I recalled reading somewhere that getting the centers last would avoid the problems with corners and edges at the end. So I tried it. I did not succeed. I ended up with swapped corners and a ipped edge anyway. Perhaps it was because of the way I tried to get the centers. I still hadnt read anyones complete solution yet. It dawned on me I should try the Edge Piece Series only with r and f instead of R and F and see what happened. It did two 3-cycles of center pieces. So I solved all the edges and corners then attempted to use my new-found center piece cycler to nish up. I got close, but couldnt gure out how to nish it up. By September 13 I had two pages of notes for solving t