Solving The Rubik's Cube in 20 Seconds - Chris Hunt - Github

* steps
  - buy a cube
  - turn the cube
    - the centres don't move, they are your reference point
    - two types of pieces, edge pieces in layers, and corner pieces (8x 4 on top layer, 4 on bottom layer)
    - learn algorithms
    - master it
- algorithms
  - notation
    - r -right, u - up, l -left, d - down, f - front, b - back
    - all moves clock-wise
    - M move notation ( middle slice one turn clockwise)
    - prime notation means move counter-clockwise
  - trivia
    - 43 quintillion 43,252,003,274,489,856,000 positions on a rubik's cube
  - 2-cycle solution (aka Bicycle)
    - focuses only on two pieces at a time
    - solves in about 2 minutes
    - requires set-up, fix and undo
    - four steps
      # swap edges (only focusing on two pieces at a time) algorithm is noted -  R U R' U' R' F R2 U' R' U' R U R' F'
        - praxis
      # swap corners (again focusing on two pieces at a time) algorithm is noted - U F R U' R' U' R U R' (I couldn't type it out fast enough before he changed the slide so it's incomplete, he's going to publish the slides)
        - praxis
      # rotate edges (again focusing on two pieces at a time) algorithm is noted - M' U M' U M' U2 M U M U M U2
        - praxis
      # rotate corners (again focusing on two pieces at a time) algorithm is noted - R' D R F D F' U' F D' F' R' D' R U
        - praxis
  - ruby gem (chrishunt/rubiks-cube)
    - kociemba two-phase solution
      - breaking down the solving into two pages, scrambled -> oriented -> solved
      - eval. sum of moves in first and second steps
    - cube explorer is an interactive program to solve and practice
  - algorithms to solve rubik's cube in 20 seconds
    - techniques: fridrich, petrus, roux, zz (or you're a genius)
    - recommend fridrich because it's the most popular (great natural progression from the bicycle solution)
    - fridrich is also known as CFOP
      - cross, solving four edge pieces
      - f2l, first two layers... build up from the cross and solve the two layers at the top and bottom of the cube
        - set-up and undo moves are all you need for this... and practise
        - praxis
      - oll (orient last layer)
        - take all pieces in the last layer and flip them
        - you'll need to memorise 57 algorithms (however, you've already learned two and that's all you need to complete... the others will make you faster)
      - pll (permute last layer)
        - take all pieces that are facing the correct direction in the last layer and move them to the right spot
        - 21 algorithms (however, you've already learned two and that's all you need to complete.. the others will make you faster)
- trivia
  - current world record is 5.55 seconds, set this year in March
- final steps: refine all the things
  - mastered friedrich
  - lubixcube.com (speed cubes w/ mods)
  - new stickers from cubesmith.com
  - bit.ly/gogaruco for silicone lubricant (for lubing the cube)
  - speedstacks.com for competition timer
  - speedsolving.com is a great community