Square-1
A cube that changes shape. You have to first make it a cube then solve it.
- WCA event
- Square-1
- Moving pieces
- 8 corners, 8 edges, 2 middle halves
- Turn size
- 30° per step
- Popular method
- Vandenbergh
Overview
The Square-1 has a top and bottom layer made of corners (wide kite shapes, 60°) and edges (thin triangles, 30°), plus a middle layer split into two halves. Turning the right half (a slice) swaps pieces between the top and bottom, which changes the puzzle's shape.
Solving happens in two parts: first get it back into a cube shape (called cubeshape), then solve it like a cube while keeping that shape.
Learning cubeshape is the hardest part for most people. After that it's a handful of algorithms, and most use the same few moves.
Notation
Moves are written as (x, y) for the top and bottom layers, then / for a slice. x and y are twelfths of a turn (30° each), clockwise, so (3, 0) turns the top a quarter turn.
The slice always turns the right half of the puzzle 180°. Hold the puzzle with the slice line running front to back.
Shape, then solve
Get the cube shape back, then solve the top and bottom layers in a few steps: corners, then edges. A final fix handles the middle layer and parity.
1. Cubeshape
Get both layers back into squares. Beginner methods first gather the pieces into a few easy to spot shapes, then use a short sequence for each shape to get back to a cube.
There are only a handful of shapes to learn, and after a while you'll recognize them instantly.
Tip: Count pieces as you go. A layer needs exactly 4 corners and 4 edges to be a square.
2. Orient the layers
Put all the top colored corners and edges in the top layer and the bottom colored ones in the bottom layer, keeping the cube shape.
3. Permute the corners
Swap corners within and between layers until all eight are in the right place.
4. Permute the edges
Do the same for the edges. Most cases are solved with one or two short algorithms.
5. Middle layer and parity
If the middle layer is flipped, or two edges are swapped with nothing else wrong (parity), use the fix-up algorithms. Parity happens on about half of solves with simple methods.
Vandenbergh
The standard speed method: cubeshape, then orient corners and edges, then permute corners, then edges and parity together. Around 60 algorithms for the full set.
Steps
Plan cubeshape in inspection: there are only a few moves in it. Learn orientation and permutation as small sets, starting with the cases you see most.
Parity tracking
Fast solvers work out whether a solve will have parity during cubeshape, and choose a version of cubeshape that avoids it. This skips the slowest step entirely.
Why it works
Each cubeshape case can be solved in different ways, and some change parity while others don't. Tracking a couple of pieces during inspection tells you which one to use.
Tips
- ★Slices are fast moves. Practice doing / with your right hand while your left keeps hold of the puzzle.
- ★Learn cubeshape properly before anything else. Guessing your way through it wastes the most time.
- ★Keep the slice line running front to back, and always slice the right side.
Resources
Ready to time yourself? The timer has Square-1 scrambles built in.
Open the timer