Pair all twelve two-piece edges — 4×4 Reduction

Before you start

All six centres are solved and in the correct order.

How to hold your cube

Use front-left (FL) and front-right (FR) as the working edge positions.

1. Find both wings of one edge

For example, both white-blue wings belong together. Matching only white is insufficient: the second colour must also agree.

Use outer turns to bring the selected wings to the FL and FR edge positions. These are the vertical edges beside the front centre. Outer turns move groups between slots without splitting their wings or mixing centre colours.

2. Place the wings in opposite horizontal slices

Choose the upper wing at FL and the lower wing at FR (or the mirrored arrangement). Arrange their front-facing stickers to be the same colour. A wide U turn can carry an upper wing across while leaving a lower wing still, forming a pair.

Before making the slice move, work out which wing Uw would bring to FR and which wing Uw′ would bring there. Choose the direction that moves the wing you want, checking both stickers before you turn.

3. Join, store, and restore

Use the chosen wide U turn to join the matching wings at FR. The centres may look mixed temporarily.
Lift the completed FR group out of the working slice with R U R' or R U' R'. Choose U’s direction so an unpaired top group replaces it at FR.
Reverse the exact wide turn from step 1. This restores the centres while the completed pair stays stored outside that slice.

Repeat. Use outer turns to move completed groups to U or D and to bring unpaired groups into the working positions. If the replacement group is already paired, choose another one; otherwise you may split your finished work.

4. Reorient a working group when needed

R U R' F R' F' R

This flips the FR group as a unit. It changes which wing is on top and which way its two colours face, while preserving the centre colours. Use it to arrange the working wings before making the slice move. A flipped last-layer edge requires a different repair.

5. Finish the last two pairs

Place the two remaining unpaired groups at FL and FR. Put the matching-colour wings in the same horizontal slice; use the FR flip above if they are in opposite slices. Now slice the selected wing from FL toward FR, perform the FR flip, and undo the slice.

For the example below, where the matching wings are in the upper slice, do Uw, then R U R' F R' F' R, then Uw'. The flip changes which wing returns, so both pairs can form. Check that both visible colours in your setup match the example before using this exact sequence.

If either pair is still mixed, inspect the other colour and adjust the working group’s orientation before retrying. Finish with twelve full pairs and six solid centres. Pairs do not need to be in their final solved locations yet.

Watch, then try

Work through an example

Start by going through the example one move at a time. It shows a specific action from a prepared position. Use the lesson’s setup instructions to recognize when that action applies to your own scramble.

Watch one worked example

This example shows how to finish the last two pairs: do Uw, the seven-move FR flip, then Uw′. The starting and ending nets show both colours of each wing. Reversing the slice move restores the centres and exchanges the selected wings.

Example grip: yellow up · blue front · red right at the start. Follow any written whole-cube rotations.

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Loading 3D cube…

Drag to inspect other faces. Use the arrow keys to rotate the view when the cube has focus.

Copy this exact example on your own cube

Start with a solved 4×4, with yellow on top and blue at the front. Apply the setup below from left to right to create the example’s starting position. Keep this practice setup separate from the scramble you’re solving throughout the course.

Uw R' F R F' R U' R' Uw'

Then follow the lesson sequence. If your cube’s colour scheme differs, match the piece relationships using your own colours.

Compare the starting position and the result

Before the example

After the full sequence

Drag each cube to inspect its other faces.

Explain it to yourself

Check your understanding

Now use your own cube

Your turn

Find two wings with the same two colours. Join them, move the completed group out of the working slice, and restore the slice. Count complete groups on both faces.

Open a 4×4 Digital Cube for practice

Opens in a new tab so you can keep this lesson open while you practise. Check for yourself whether you’ve met the lesson goal. The Digital Cube doesn’t grade your work.

If you get stuck

A completed edge splits when I restore the slice.

Move the pair out of the active horizontal slice first, then bring an unpaired group into its place.

The final two pairs are still mismatched.

Check that the matching wings are in the same horizontal slice before you slice, flip, and slice back. Compare both outward-facing colours with the example.

Before moving on

Check your result

4×4 lesson result: All twelve edges are paired. The two wings of each edge match on both faces, and the centres are restored. You can now treat each pair as a single edge in a 3×3 solve.

Your cube at this stage

All twelve edges paired

The two wings of each edge match on both faces, and the centres are restored. You can now treat each pair as a single edge in a 3×3 solve.

Confirm these on your cube. Watching the animation alone does not complete the lesson.

Each of the twelve edges has two wings whose stickers match on both faces.All six centres are restored after pairing.I can distinguish a complete but reversed pair from two unmatched wings.

Check off each item once you can do it yourself.