Glossary

Cube terms

Algorithm (or alg) : A memorised sequence of moves that produces a precise effect while leaving the rest of the cube intact.

AUF (Adjust Upper Face) : The little U or U' you do before or after an algorithm to line it up. It does not count as part of the algorithm.

Centre : A piece with one sticker. The six centres never move relative to each other: they define the colour of each face.

Commutator : A sequence of the form "do A, do B, undo A, undo B". It disturbs only a very small part of the cube. R' D' R D is one.

Corner : A piece with three stickers, at a vertex of the cube. There are 8.

Edge : A piece with two stickers, between two centres. There are 12.

Headlights : Two corners of the same colour on one face, with a different edge between them. Used to recognise PLL cases.

Orientation : The way round a piece is placed. A piece can be in the right spot and badly oriented.

Pair : A corner and the edge that goes right next to it, handled together. The basis of F2L.

Permutation : The place of each piece, regardless of which way round it is.

Slot : The home of a corner + edge pair in the first two layers. There are four.

Methods and steps

CFOP (or Fridrich method) : The competition method: Cross, F2L, OLL, PLL. 78 algorithms in total.

Cross : The first-layer cross. First step of CFOP.

F2L (First Two Layers) : The first two layers, solved as corner + edge pairs. 41 cases, but learned intuitively.

4LLL (4-Look Last Layer) : The last layer in four steps instead of two. 16 algorithms instead of 78. The natural bridge between the beginner method and CFOP.

Lookahead : Hunting for the next piece with your eyes while your fingers execute the current sequence. The skill that separates the levels.

OLL (Orientation of the Last Layer) : Making the whole top face yellow, without caring about the places. 57 cases.

PLL (Permutation of the Last Layer) : Putting every piece of the last layer in its place. 21 cases.

The algorithms that have names

Named perms (A, E, F, G, H, J, N, R, T, U, V, Y, Z) : The 21 PLL cases, named after the shape drawn by the movement arrows.

Sexy move : R U R' U'. The most used sequence on the cube. Repeated six times, it returns to the starting point.

Sune : R U R' U R U2 R'. Orients three corners. With its mirror the anti-Sune (R U2 R' U' R U' R'), it is the first real OLL algorithm to learn.

T-perm : R U R' U' R' F R2 U' R' U' R U R' F'. The best-known PLL: it swaps two corners and two edges.

Measurements

Ao5, Ao12 (average of 5 / of 12) : The average over 5 or 12 solves, dropping the best and the worst time. It is the official measure in competition, far more reliable than an isolated record.

HTM (Half Turn Metric) : A way of counting moves: a half turn (R2) counts as one move.

Inspection : The 15 seconds allowed before the timer starts, to plan the cross.