ZZ TutorialStep 1: EOCross

How to solve EOCross

By S1neWav_ and crystalcuber

Introduction

EOCross is the first step of the modern ZZ method. We solve two properties:

A solved EOCross looks like this:

The turquoise stickers are there to show the orientation of the unsolved edges. Good edges have turquoise on the “purple orbit”. We can see that they’re all good.

Frequently asked questions

What’s the purpose of EOCross?

EOCross slows down the beginning of the solve compared to just solving CFOP cross. However, EOCross sets up a rotationless, ergonomic F2L step. With EO solved, there is a simpler way to deduce F2L edges. Last Layer also becomes simpler. OLL and PLL is easier to learn for ZZ (28 algs instead of 78), or you can learn full ZBLL and use it every solve.

Should I learn EOLine first?

We don’t recommend EOLine as a stepping stone to EOCross for two reasons:

  1. EOLine F2L is fundamentally different from EOCross F2L, doesn’t make sense to learn both types.
  2. EOCross is hard at first, but using it from the start will help build inspection skills.

In this tutorial, we’ll solve EO first and then cross separately. For speed, you can later learn how to solve this as one step in the Improvement Guide.

Step 1: EO

The first step is to solve edge orientation. This process is explained in our EO tutorial.

Step 2: Cross

Once EO is done, solve the four cross edges. All you need are the “natural” R, U, L, and D moves, and you can also use F2 and B2.

If you know CFOP or Beginner’s method, you are already familiar with solving a cross. Just make sure you avoid moves that disrupt EO such as cube rotations, quarter-turn F/B-layer moves and slice moves.

If you don’t have experience with cross, expand the below section to learn more.

How to solve cross

Our goal is to solve the cross edges: the four edges that belong to the bottom layer of the cube. Cross edges always have the color of the bottom face, so that’s how you find them.

We need to move all cross edges to the bottom, because that’s where they belong solved. To move an edge to the bottom, use R/L moves, F2 or B2 (whichever one that moves the edge).

Sometimes, there will be a bottom cross piece that will get “kicked out” when you move another edge to the bottom. This can be avoided by doing a D-layer turn to move the bottom cross piece out of the way. To move this blue-white edge to the bottom, we can first do D' to move the red-white edge out of the way. Then we can do R'.

Now we know how to move any cross edge to the bottom. We could put all cross edges on the bottom, and it would look like this.

However, this is not a solved cross! Our goal is to solve the cross pieces, which looks something like this:

You can see that the colours match between the edges and the front/left/right/back centers.

In order to match the edges with the centers, let’s first take a look at how centers are positioned.

Centers never move around the cube. So there are relationships between their colors that never change. For example, the blue and green centers are always opposite each other, and the blue center is always next to the orange center.

We need our cross edges to have the same color relationships as the centers. That way, at the end of our cross solution they will line up with the centers. It would be too restrictive for our solution to keep the solved edges matching the centers at all times.

Here’s an example where we use these relationships to solve cross:

There are already two cross edges at the bottom, but they don’t have the right relationship. With white as our bottom color, the red center is to the left of the green center. However, the cross edge with red is to the right of the cross edge with green.

We can fix that by replacing the green-white cross edge with the blue-white cross edge.

Move: R

Now the two edges at the bottom have the right relationship. The blue center is to the left of the red center, and the blue edge is to the left of the red edge.

We can continue moving edges down while maintaining the right color relationships. We can do D2 R' to place the blue cross edge opposite to the green cross edge, just like how the blue and green centers are opposite.

Now there’s only one remaining cross edge, on the left side. We can finish with D L'.

Example EOCross


Scramble: R2 F2 R2 D2 B2 U' L2 R2 B2 U' L2 D L2 B' U' L R U2 F' L' F2 D2

Solution:

Troubleshooting

If you find that edges are unsolvable or end up twisted in their spot, it means EO is not complete yet. Make sure that all edges are good before solving cross.

Influencing

Once you are comfortable with EOCross, you can improve your solutions with a technique called influencing. This means changing your EO solution to make the resulting cross better. Start paying attention to the direction of F and B turns during EO (deciding between F and F’ for example).

Here are some examples of basic influencing:

There are many forms of influencing, click here for more details.

What’s next?

We suggest doing some untimed EOCross solves to become more familiar. The next step is ZZ First 2 Layers.