The HD method (short for the Higgs-Demars method, named after its creators) is an intermediate 2x2 method that is similar in speed to CLL.
The HD method consists of three steps:
- V: solving 3/4 of an Ortega face on the D-layer (intuitive, ~1.5 moves)
- LOLS: orienting the remaining 5 corners of the cube (23 algorithms, 5.5 moves)
- NLL: solving the rest of the cube in one algorithm (36 algorithms, 8.13 moves)
The V is the first step of the HD method and by far the easiest. For this step you intuitively build 3/4 of a face on the D-layer. The V requires no algorithms and averages about 1.5 moves per solve. The maximum number of moves for a V is 3. Here are 50 sample V's provided by Jonathan Lewis.
LOLS (short for Lewis Orientation of the Last Slot) is the second step of the HD method and consists of 16 algorithms (plus the 7 well-known OLLs). The aim of this step is to have the U or D-layer color facing up on the remaining five unoriented pieces. The algorithms for this step were created by Jonathan Lewis (also known as Shiv3r) and V. Higgs (also known as Thermex). The average movecount for an LOLS algorithm is about 5.5 moves and many of the algs are under 5 moves.
NLL (short for Neuro Last Layers) is the last step of the HD method and requires the most algorithms of any step (36). The algorithms permute the V, place the DFR corner in its slot and also permute the U-layer corners. Just like the LOLS step, the unsolved D-layer corner should be held in the DFR position. Most of the NLL algorithms were made by Neuro.
The HD-G, or HD-Guimond method is a variant of the HD method where the V and CO steps are done simultaneously and (semi) intuitively in about 3.90 moves on average. This is done similarly to the first step of the Guimond Method, hence the name. The biggest difference is that the last move of the CO case may be changed, or more may be added, to ensure that a V is formed on both opposite faces. This is an advanced variant, and less suitable for beginners.
- The HD method contains a fairly reasonable number of algorithms; it only has a few more algorithms than CLL and far less than full EG. Plus, many of the algorithms are less than 5 moves, making them effortless to memorize.
- The HD method is pretty easy to one-look (see below) since the V is only 1 or 2 moves on average and the rest of the solve is algorithmic.
- HD has a pretty low movecount, comparable to CLL and EG.
- The HD method is very different from most mainstream methods and can be difficult to learn and master for someone transitioning over from a method like LBL or Ortega.
- Nothing about HD really stands out, and there are other 2x2 methods with less algorithms that can achieve similar movecounts.
- The HD method is still in development, and many algorithms require improvement.
One of the main advantages of the HD method is how simple one-looking and two-looking a solve can be. The V can easily be one-looked as it is only one or two moves on average. After that, the solver should be able to see what LOLS case comes after solving the V. If the solver can see this far during inspection they can successfully two-look the solve, leaving only the NLL step, which can either be seen once the V and LOLS cases are executed (two-looking) or during inspection along with the other steps (one-looking). In order to one-look the solver needs to see the permutation of the pieces in the LOLS case and understand how the LOLS cases effect permutation of the pieces. The document showing how permutation is effected during LOLS can be found here.