Step 2

In step 2, we insert the front edge and simultaneously orient the top edges. This takes 5.71 moves on average, from any configuration.

If you were able to orient some edges during step 1, then step 2 will be shorter.


Step 2 is not too difficult to understand. Below, I will explain some strategies that you can use so that you won't have to memorise any algorithms.

If you prefer to just memorise a table of optimal algorithms, I have prepared two tables:

  1. Table of 13 algorithms, allowing you to average 6.01 moves.
  2. Table of 25 algorithms, allowing you to average 5.71 moves.

Strategy 1 - simple swap

Here is a typical position you might see in step 2. Focus on the orientations of the red edge pieces (that is, the directions in which the the red edges are facing). The red edges on top can be facing either up (correct) or outwards (incorrect). There is one correct red edge on top and two incorrect ones. The 4th red edge is down in the middle layer. It can also be facing in one of two directions: to the left, or to the right. This time it is facing to the left.

Whichever way the front/middle edge is facing, it can always be moved to the top with correct orientation in just one move. This is because there are two ways to move it to the top. Click play. Notice that moving it via the white side will make the red face upwards, but moving it via the green side will make it face outwards.

If we move the front/middle edge up to the top (with correct orientation), and swap it for an incorrect red edge, we will then have two red edges on top facing upwards. Click play. If we keep swapping edges like that, step 2 will eventually be finished.

Continuing on from this position, apply the same strategy. This time, the front/middle edge is facing to the right. To move it up to the top with correct orientation, we must go via the green side (click play). Each time we do this, there will be one more red edge on top facing upwards.

Finally, there are no more incorrect red edges on top, so we just swap the front/middle edge with the piece that actually belongs in that position. This is always the last piece to be swapped. After that is done, step 2 is complete.

Strategy 2 - criss/cross

When you have many incorrect edges bunched together, you can use the criss/cross maneuver. To see how that works, press play. Study it, and look for opportunities to use it.

Using the criss/cross maneuver in combination with the simple swap, this position can be solved in 6 moves.

Strategy 3 - reassigning the free column

The "free column", situated at the front, is a source of power in steps 1 and 2. It gives us an additional degree of freedom for maneuvering pieces around.

Since the square shape is regular, it is possible to rotate a step 1 square, and reassign the free column to another column. The animation to the left shows how we can move the free column left one position.

This position can be solved by reassigning the free column, doing a simple swap, then returning the free column to its original position.

Reassign the free column plus criss/cross.

Criss/cross + reassign the free column + another criss/cross.