Step 4

In step 4, the last four pieces of the cube are correctly put into place.

There are 42 possible cases in this step, and each case is indexed by the number of corners that need to be twisted:

• 0 corners
• 2 corners --- 3-colour version
• 3 corners --- 3-colour version
• 4 corners --- 3-colour version

The 3-colour versions can help you to recognise the different patterns by identifying opposite colours. This recognition technique is powerful, since the patterns will still be recognisable even if step 1 leaves parts of the cube upside down.

These step 4 algorithms were generated by Bernard Helmstetter using a computer program he developed. You can find his original table here.