Recognising cases

How to tell cases apart quickly, set by set.
Recognition is often slower than execution. Good recognition looks at as few stickers as possible: usually the top face and two adjacent sides, so you never need to tilt the cube. Each algorithm set's page has a recognition section; the essentials:
  • •
    OLL: Count the top-colour stickers on the top face's edges: none is a dot; two opposite is a line; two adjacent is a L; all four is a cross. Then look at the corner stickers on the sides for headlights and bars.
  • •
    PLL: look at two adjacent sides, and glance at the other two. Headlights on all four sides of the top layer: solved (an EPLL: U, H or Z). Headlights on exactly one side of the top layer: adjacent swap. No headlights on the top layer: diagonal swap. Then read blocks of two or three.
  • •
    COLL and CMLL: the top face gives the corner shape (Sune, Pi, H...); the side colours of the corners give the permutation.
  • •
    ZBLL: corner shape, then the COLL case, then the edges relative to the headlights.
  • •
    F2L: find the corner, see where its cross colour points, then whether the edge is joined to it.

OLL

57 cases · Make the top face one colour in one algorithm: 57 cases.

PLL

21 cases · Move the oriented last-layer pieces home: 21 cases.

COLL

40 cases · Orient and permute the corners together, keeping edges oriented: 40 cases.

CMLL

42 cases · Solve the four top corners after both Roux blocks: 42 cases.

F2L

41 cases · Pair a corner with its edge and insert the pair: 41 cases per slot.
The trainer drills exactly this: it shows a case diagram and asks you to name the case before showing the algorithm.