13 cases
Four steps and a handful of algorithms to finish the cube.
Finishing the last layer the beginner way splits into four steps: make the cross on top, orient the corners, put the corners in the right places, then the edges. Six short algorithms cover all of it, and two of them are the same sequence applied differently.
A bar of three across the middle of the top face, running from the left edge to the right. The front and back edges are flipped, showing their top colour on the side faces instead. Ignore the corners entirely at this stage — they are allowed to be anything.
Two flipped edges meeting at a right angle: the back edge and the left edge are the correct way up, forming an L that points into the back-left corner. Held like that, the elbow of the L is at nine and twelve o'clock.
Nothing on the top face but the centre. All four edges are flipped, each showing its top colour on a side face. There is no orientation to hunt for, so start from wherever the cube is.
The cross on top is done and exactly one corner already shows the top colour on top — hold it at the front left. The other three show their top colour on the back face, on the right face and on the front face in turn.
One corner done again, but the twist runs the other way. Hold the finished corner at the back right and the other three show their top colour on the left face, on the front face and on the right face.
No corner shows the top colour on top. All four top-colour corner stickers face outwards on two opposite side faces — two on the left and two on the right as drawn — so the case looks the same from either side.
No corner done, and this time the loose stickers are unevenly spread: two of them sit side by side on one face — the left as drawn — with a single sticker at the far end of the front and another at the far end of the back.
The top face is one colour, so read the side stickers instead. Exactly one corner has both its side stickers matching the centres beside it — hold that corner at the front left. The two back corners then show the same colour as each other on the back face.
Indistinguishable from the case above at a glance: one corner home, the rest wrong. Hold the home corner at the front left again and the two right-hand corners show the same colour as each other on the right face.
The top cross is finished and all four edges are already in the right places, but the corners are a mess of orientations. One corner — the front right as drawn — is in the place it belongs; the other three are each in the wrong place and turned the wrong way.
Everything is solved except three edges. One edge is already home — hold it at the back — and the other three need to move round: the left edge belongs on the right, the right edge belongs at the front, and the front edge belongs on the left.
The same picture with the cycle reversed. Solved edge at the back again; now the left edge belongs at the front, the front edge belongs on the right, and the right edge belongs on the left.
Every edge is wrong, so there is no solved one to hold at the back. Here the front and left edges want to swap with each other and so do the back and right — two swaps rather than a cycle.