Here is my technique for doing the cube blindfolded starting with the 2x2x2 cube. (My record for memorizing the 2-cube for solving purposes is 12 seconds to give you an idea of efficiency.) It needs a good memory for numbers - my memory for the J. Fridrich moves is only good for half of them so far but my number memory is good). 1. Orient the cube so that the DBL corner is in the correct position and oriented correctly (of course, this is automatic unless you have a specific corner in mind - I always have white as up face and green as front face when blindfold solving the 2-cube so I have the blue-yellow-orange cube as DBL with blue on the bottom.) 2-3. (It doesn't really matter which order you do these in.) Figure out the permutation of the first 7 corners - technically, you only need to remember the first 6 as since you have corner 8 in position that automatically gives corner 7). For this purpose, my corners are labelled as follows: Up Face, Front Face, Right Face, count as 0, Down Face counts as 1, Back Face as 2, Left face as 4. (Then add 1.) So it is like binary. For instance the white-green-red corner is corner 1. I then remember the sequence, e.g. 2 5 3 6 1 7 4 (I do actually take the 4 on board although it is not strictly necessary - see above). For the orientations, I remember the positions of the corners that need one twist and the positions of the corners that need 2 twists. There will always be at least one other corner (than corner 8) that doesn't need twisting. That's all. I don't blindfold cube for speed. I work out the solution after the blindfold part. Part of this involves continuously having to change the permutation in your mind whern you get to that point. Here is my technique. First of all, orient the corners - after you do this you can forget about them if you only use orientation preserving moves. For this purpose, I use 2 of the J. Fridrich sequences: (e.g. to twist UFR twice and DFR once) R'D'LDRD'L'D followed by UL'UR2U'LUR2U2. Now for the permutation algorithms: I basically don't want to even possibly mess up so I only use the one algorithm which is the corner 3-cycle. Using corner 3-cycles only with corners in the U face or D face preserves orientation. (If you need to swap corners between these faces you may need to do a move like F2 or R2 etc. first and then cycle them out.) OK, so by doing this you can get at least 6 corners in the right position and you can ensure that if 2 are bad then they both lie in the U face or the D face and that they are adjacent. If there are 2 to switch the original permutation of corners was odd. This can be overcome by turning the U (or D) face once to get one of those corners in position leaving a 3-cycle to complete the work. Further advice on solving the cube blindfolded can be seen on my webpage: www.math.columbia.edu/~carr/BC.html (actually, this is for the 3x3x3 cube; it's a bit boring perhaps, as for a number of the earlier cubes I went into great detail about how I solved each one. Later I just recorded the position of the cube(s) - since you can't write down the details in advance, it is possible that I may have a couple of errors in it, but it is correct to the best of my memory.) Anyway, you can get techniques on solving the 3-cube blindfolded there too. I'll discuss this as it may be of some interest. The idea is much the same except you can't ensure that any corner is in place to start: there are 4 things to memorize corner permutation edge permutation edge orientation corner orientation The hardest is probably corner orientation because you have to remember not only the positions of the corners to twist but also how many times. Next comes edge permutation as it is 12 things to remember (although you could remember just 11). The other bits are fairly easy. The technique I use is currently just to keep white up and green front (but I have on occasion done others) as then I know the numbers for the edges and corners and can memorize faster. Corners are labelled as before and edges are labelled 1-12 thus (UF, UB, UR, UL, DF, DB, DR, DL, FR, FL, BR, BL - thus the faces are prioritized U, D, F, B, R, L and labelling follows this - this is also helpful for remembering orientations). Edge orientation is 0 (correct) is the edge has its high priority colour in the higher priority face and 1 (incorrect) otherwise. e.g. If the white-green edge is in the FR position it has orientation 0 if the white part is in the front face and 1 if the green part is in the front face - since white (being the colour of the up face) has higher priority than green (being the colour of the front face) and the front face has priority over the right face). The technique is then to orient stuff before permuting. Use 3-cycles to permute - there may be a signature problem with the permutations (i.e. you may have to switch just 2 corners at some point say). In this case, I usually try to get the corners adjacent and switch them with 2 edges in a T-formation. C E C E This may be done after permuting various other edges. 3-cycling edges in the U,D,R,L faces preserves orientation of edges but in the F,B faces it changes the orienation of 2 edges so I don't 3-cycle in those faces. I use a couple of other moves sometimes too. e.g. (F2R2)3 does a double transposition switching edges UF with DF and UR with DR (and preserving orientations). Also Rs2F2Rs2B2 switches edges UF with DF and UB with DB etc. I don't always do this but if you try to place the edges in the middle layer (9-12) or in one of the other layers, if you prefer then you can cut out a part of the permutation you need to remember. A move I rarely do but may, if I remember it is (F2R2)3R(U2R2)3R' which 3-cycles edges in positions DF->UB->UF. You can simplify it by cancelling some Rs e.g. (F2R2)2R(U2R2)2U2R'. I haven't mentioned orienting the edges yet: I use 2 moves here (again from the J. Fridrich set) First is LsFRsU2LsFRs followed by B2U'RsB2LsU'B2 (which flips UB and UL edges). Second is FsUF'U'Fs'LFL' followed by F2ULsF2RsUF2 (which flips UR and UL edges). My record for memorizing the 3-cube is 167 seconds. For multiple cubes it gets a bit harder - I only have 2 3x3x3 cubes so I can't go for the record but I can do 2 cubes. The hardest thing is trying not to get confused over which stuff belongs to which cube. I always take the cube with the harder orientations first as this is the hardest bit to remember (for me). Since that bit is done first, it takes out the hard part at the start. I haven't tried a 4x4x4 blindfolded (my old one broke so I can't, unless I use a subset of a 5x5x5 which might be confusing) but I have a fair bit of theory behind it and think it is quite possible. My technique here would be: orient corners, solve the centres without disturbing edges or corners (I used to do this at the end when solving big cubes), permute corners 3-cycle edge components without altering anything else to solve edges solve like a 3x3x3 cube blindfolded if needs be flip one edge using C Hardwick method. Hope this is of some use, Dr. C.