Fewest Moves techniques
This page introduces some tips and techniques to help you solve the cube in as few moves as possible.
The best results can be obtained when all techniques are controlled. It is strongly advised not to follow a strict pattern, for example a speedsolving method. However some algorithms learned from a speedsolving method will give some advantages in some cases. The most useful methods are Heise, Petrus, Fridrich, Roux and ZBLL.
Best start for an FMC is block building technique. Try to build a 2x2x2 block then a 2x2x3 block. After the 2x2x2 block you have 3 sides to extend it to a 2x2x3. Explore all of them. After the 2x2x3 block...
When inserting Fridrich-pairs in F2L don't get stuck with you speedcubing methods but try some alternatives and check each of them for...
If you can't find a good start to your scramble, you can try inverting the scramble. That means the scramble R F' D2 U becomes U' D2 F R'. Find a good solution based on the inverted scramble, then invert the solution. The inverted solution will solve the original scramble. It looks strange to solve like this, but gives you more chances to find a good start.
Pseudoblocks or Pre-scramble-moves
Like Heise Method you can build pseudo blocks, which are adjacent 1x2x2 blocks or c/e pairs that are not adjacent but need an extra turn to get those blocks at the right color-centre. Solving with pseudo blocks can be very difficult and requires a lot of experience. As an alternative you can replace a pseudo block by a pre-scramble-move to give more oversight over your solve.
The Normal-inverse-scramble-switch (NISS) technique was introduced in 2009 by Guus Razoux Schultz in the speedsolving forum here: http://www.speedsolving.com/forum/showthread.php?13599-The-FMC-thread/page19&p=258791#post258791 On this forum you can find several good explanations of how it works. Mike Hugley made it pretty understandable with the following description:
Generally, you use premoves to modify a scramble so you can solve it more easily. The most common approach for this is to solve a "pseudo-block" of some sort, where for instance you might put in a corner-edge pair of the wrong color into a 2x2x2 or 2x2x3 block. Then you find the moves necessary to put that corner-edge pair (or whatever) into it's proper location in the solved cube. If you then apply those moves to the solved cube prior to applying the scramble, you'll find that the pseudo-block becomes an actual block. Then you can add those moves to the end of your final solution and it will be solved.
Guus's solution you mention is using "NISS" - his "normal-inverse-scramble-switch" method, where you solve part of the cube with the normal scramble, then when you get stuck, you switch to the inverse scramble and use it, then when you get stuck again, you switch back to the normal scramble, and so on. I love NISS - it's really fun to do! Anyway, when you switch from normal to inverse scrambles, the moves you used at the beginning of the normal scramble solve become premoves to the inverse scramble (and vice-versa). It takes trying it to see how it really works, and it's really quite ingenious.
The best way to understand these is to look at some of the solves that others have done (like the ones in the weekly competitions) and understand how they work. Examples are much more useful than descriptions - this isn't a particularly good description, but maybe it gives you an idea of what's going on.
A pre-scramble move is a move you apply before the scramble and which allows you to find more possible solutions. Of course you must not forget to add the premove at the end of your solution.
Inserted Moves (single)
Sometimes after a promising start you can't find a good continuation. Say you have solved a 2x2x2 block, but after that there's nothing good. By stepping through the solution you might see that at one place there's no 2x2x2-pieces on U, at that place you can try to insert U, U' or U2 and see if a better continuation is possible.
A very powerful technique in FMC is to solve everything except 3-5 corners and then insert 8 move commutators that cycle three corners earlier in the solution. Since there many corner configurations that can be solved in 8 moves often one will cancel moves, and thus one corner cycle will add less than 8 moves to the total solution length. Edge cycles are not used as often since FMC is judged in HTM and edge cycles often involve slice moves that are counted as two moves. Some people use stickers to more easily track the unsolved pieces through the solution.
If you see some opportunity to solve a lot of blocks without any (known) pattern you could try to solve it. When leaving a maximum of 4 edges and 4 corners try to conjugate them to 1 face during a solve. Then use pre-scramble-moves or a second cube to solve that face / LL
sometimes you solve a lot of LL blocks using a very short LL algorithm, 8 or 9 moves maximum. Try to learn short LL algorithms in such a way that you know what it does to corners and edges. Start with the length-6 LL-alg, then the three 7-move LL-algs, the five 8-move LL-algs, and so on. You are really an expert when learning all LL-algs up to 10 moves.
- Do not use moves that turn the cube!
- Use fixed colors for up & front to enhance recognition!
- Better still, look at the centre of the face you are turning, it tells wich side it is ("White" = U and so on), then orientation does not matter anymore.
- Write down promising moves, do not wait till the very end!
- Create a backup solve!
- Learn to scramble fast, it can save a lot of time during a 1-hour solve.
- Bring stickers (for insertions) and extra cubes during a competition.
- Ryan Heise's page on intuitive solving techniques
- Speedsolving.com Fewest Moves: Tips and Techniques
- Speedsolving.com The FMC thread
- Speedsolving.com 6 to 10-move LL algorithms
- Online tool: Insertion Finder