4×4 Yau Method

The Reduction Method has three basic steps: solve the centers, pair the edges, and solve as a 3×3, starting with the cross.

The Yau method intermixes those steps to solve specific centers and pair specific edges early, completing the cross in the process. The steps are as follows.

1. Solve the bottom and top centers.
2. Pair and position three cross edges.
3. Solve the remaining four centers.
4. Pair and position the remaining bottom layer edge.
5. Pair the remaining edges. After this step, all six center groups should be solved, all twelve edges should be paired, and the cross step should be complete.
6. Solve the rest of the puzzle as a 3×3, starting with F2L.

Pairing and positioning three cross edges is easier when only two centers are solved, because the unsolved inner layers provide a free workspace for pairing and positioning wings. By completing the fourth cross edge before pairing the remaining edges, Yau eliminates the need to solve the cross during the 3×3 stage. Because Yau makes edge pairing and cross more efficient, it is faster than Reduction for many experienced cubers.

Step 1—Solve the bottom and top centers

Complete the bottom center first, then the top, as in Reduction.

Before proceeding, change the orientation of the entire cube so that the bottom center is on the left and the top center is on the right. This is a rotation around the Z axis to change the orientation of your puzzle. With the cube in this orientation, you should be able to perform Rw turns without breaking your two completed centers.

Remember that your bottom center is on the left. As you pair cross edges, you’ll position them on the left, not the bottom. You’ll work with the cube in this orientation through Step 4.

Step 2—Pair and Position Three Cross edges

Use Rw turns and outer-layer turns to pair one of the cross edges. Position it on the left side, adjacent to the completed bottom center, with the markings matching the bottom center facing left.

Repeat, taking care to not displace the previously positioned cross edge. Position this second cross edge relative to the previous pair based on the arrangement of markings on your cube.

Repeat to pair and position a third cross edge on the left side of your cube. Do not displace existing edge pairs.

Verify by touch that the left side of your cube contains the solved bottom center with three cross edges. The left side should feel like a cross missing one edge. Verify by touch that the non-bottom markings of the three cross edges are in the correct arrangement for your cube. Verify that the top center remains solved on the right side of your cube.

Before proceeding, turn the L side so that the remaining unsolved cross edge is in the left top location.

Feel the left side of your cube. The solved cross edges should be in the left back, left bottom, and left front locations. Only the left top edge should be unsolved. With your cube in this orientation, you should be able to perform both U and Rw turns without breaking or displacing the bottom center, top center, or any of the three cross edges.

Step 3—Solve the remaining four centers

In Reduction, the remaining four centers are commonly solved after the bottom and top centers. Because no edges have been paired and positioned, any outer layer can be turned in the process.

When solving the remaining four centers in Yau, three cross edges are already paired and positioned. To avoid breaking or displacing those edges, restrict your turns to U, Rw, and l (left inner slice).

As a tip, think of the U side as your workspace. Build pairs of center pieces in U, then position them with l or Rw turns, taking care not to disrupt each center after it’s solved.

As another tip, use a right triple layer turn when necessary to bring a group of centers to the U side workspace. A right triple layer turn is an Rw turn that includes the l inner slice. In other words, turn everything except the left side.

As a third tip, don’t turn the left face or change the cube’s orientation. Always keep the missing cross-edge position at left-top.

Because solving the remaining four centers is more restrictive with Yau, this step may initially feel frustrating and slow. Be patient. Keep trying. Eventually, you’ll be able to solve the remaining four centers quickly, without disturbing the cross in progress.

Before proceeding, verify by touch that all six centers are solved and in the correct arrangement for the markings on your cube. Verify that three of the four bottom layer cross edges are still positioned correctly relative to each other.

Step 4—Pair and Position the Remaining Bottom Edge

To complete the cross, pair the two wings belonging to the remaining cross edge, then position the completed edge.

You could pair them using the single edge pairing method, but there is a more complex method that may be faster.

Conceptually, split the centers with an Rw (or Rw′), place a second wing across the working side opposite the first, then pair them with an Rw′ (or Rw).

The specifics vary by orientation and starting position of the wings. Covering all possible scenarios would be impractical.

Here is one concrete example. 

1. Examine the puzzle and find the final two cross wings.
   • The first is in the left wing position of the top front edge, with its bottom marking facing F.
   • The second is in the back wing position of the right bottom edge, with its bottom marking facing D.
2. Perform an Rw turn to split the centers. Track the second wing location, because the Rw turn moves it. Notice that the wings aren’t yet aligned for pairing. If the second wing occupied the right wing position of the top-back edge, an Rw′ turn would pair them.
3. Perform a U turn.
4. Perform an R turn so that the second wing is in the front wing location of the right top edge.
5. Perform a U′ turn.
6. Perform an Rw′ turn to restore the centers and pair the wings.
7. Perform a final U turn to position the final cross edge.

There are many different starting positions. Repeated solves will increase your experience with this step.

When the cross is complete, perform an L turn to align the cross edges with their corresponding centers. Finally, return your cube to its normal orientation, with the bottom and cross facing down and the completed top center facing up.

Step 5—Pair the Remaining Edges

A common technique for solving the remaining eight edges is called 3-2-3. This pairs three edges, then two, then the final three.

However, when the arrangement of wings permits, I prefer a 3-3-2 method. Using the triple edge pairing method, I pair three edges with a Dw turn, then another three with a Dw′ turn. I pair the final two using the double edge pairing method.

Teaching 3-2-3 is beyond the scope of this guide. Although it may be more efficient for certain wing arrangements, the 3-3-2 method works well for me and uses techniques already described.

Step 6—Solve as a 3×3

With the centers solved, the edges paired, and the cross completed, solve the rest of the puzzle as a 3×3, going immediately to the F2L step. As with the Reduction Method, resolve parity if you encounter it.