Unlock the Cube: Solve a Rubik’s Cube in 20 Moves (God’s Algorithm Simplified)
Have you ever stared at a scrambled Rubik’s Cube, feeling utterly defeated? The colorful squares seem to mock your attempts at solving it. You’re not alone! Millions have faced the same challenge. But what if I told you that *any* Rubik’s Cube configuration can be solved in 20 moves or less? This is known as “God’s Algorithm.”
While knowing the absolute shortest solution requires complex computer algorithms and massive databases, this article provides a practical, simplified method to get you solving the cube consistently and efficiently, often approaching the theoretical minimum move count. We’ll break down a proven layer-by-layer method that’s easier to learn and remember. Get ready to impress your friends and finally conquer that cube!
## Why 20 Moves? Understanding God’s Algorithm
The concept of God’s Algorithm stems from computational analysis. Researchers explored every possible Rubik’s Cube configuration (of which there are over 43 quintillion!), determining the *maximum* number of moves required to solve any given state. That number is 20. Think of it as the absolute most efficient solution, achievable by a hypothetical ‘perfect’ solver.
While we won’t be using a true God’s Algorithm here (those are incredibly complex), we’ll be using an advanced layer-by-layer method that often results in solutions within a reasonable proximity to that optimal number.
## The CFOP Method (Simplified for Efficiency)
The method we’ll use is a streamlined version of the CFOP (Cross, F2L, OLL, PLL) method, one of the most popular speedcubing techniques. We’ll simplify it by focusing on intuitive moves and fewer algorithms to memorize, prioritizing understanding over pure speed initially. As you get more comfortable, you can refine your technique and explore more advanced algorithms.
**Cube Notation: The Language of the Cube**
Before we dive in, let’s understand the standard notation used to describe Rubik’s Cube moves. It’s crucial for following the algorithms:
* **F:** Front face (the face facing you)
* **B:** Back face (opposite the front face)
* **R:** Right face
* **L:** Left face
* **U:** Up face (the top face)
* **D:** Down face (the bottom face)
Adding an apostrophe (‘) after a letter indicates a counter-clockwise turn. A letter without an apostrophe means a clockwise turn. Adding a “2” after a letter means a 180-degree turn. For example:
* **R:** Rotate the right face 90 degrees clockwise.
* **R’:** Rotate the right face 90 degrees counter-clockwise.
* **R2:** Rotate the right face 180 degrees.
**Getting Started: Preparation and Pre-Inspection**
1. **The Scramble:** Ensure your cube is thoroughly scrambled. Use an online random cube scramble generator for the best results. This will provide a fair and challenging starting point.
2. **Cube Quality:** A smooth-turning cube is essential. Consider investing in a good speedcube. It will make the learning process much more enjoyable.
3. **Color Scheme:** Understand your cube’s color scheme. Opposite faces will always have the same colors on all cubes. (e.g., white opposite yellow, blue opposite green, red opposite orange). This consistency helps with orientation.
4. **Pre-Inspection:** Before you start timing yourself (if you’re aiming for speed), take a few seconds to inspect the cube. Look for easy moves to start the cross or identify promising pairs for the first two layers (F2L). This pre-planning saves valuable time during the solve.
## Step 1: The Cross (Orienting the Edge Pieces)
The goal of the cross is to place the four edge pieces of one color (usually white) correctly on the *bottom* face, so they also match the colors of the adjacent center pieces.
1. **Choose a Color:** Select the color you want to solve the cross on (e.g., white). This will be the color of your bottom face.
2. **Find the Edges:** Locate the four edge pieces that contain your chosen color. They will be scattered around the cube.
3. **Bring Edges to the Top Layer:** The primary objective is to maneuver these edge pieces to the *top* (Up) layer. Use simple turns (U, D, R, L, F, B) to achieve this. Don’t worry about orientation yet, just get them on the top layer.
4. **Orient and Position Edges:** Now, we need to get each edge piece to its correct position and orientation on the bottom layer. This involves two steps:
* **Matching Colors:** Rotate the top layer (U moves) until the color on the side of the edge piece matches the color of the center piece below it on one of the four side faces.
* **Moving to the Bottom:** Once the colors match, use one of the following sequences to move the edge piece to the bottom (Down) layer, correctly oriented:
* **If the matching color is on the front:** F2 U’ F’ (Often called the ‘Sexy Move’)
* **If the matching color is on the right:** R U’ R’
* **If the matching color is on the left:** L’ U L
* **If the matching color is on the back:** B2 U’ B2
5. **Repeat:** Repeat step 4 for all four edge pieces. Once you’ve completed this, you should have a white cross on the bottom face, with all the edge colors matching their respective center pieces.
**Tips for the Cross:**
* **Plan Ahead:** Look for edges that are already close to their correct positions. Try to solve the cross in as few moves as possible.
* **Avoid Disrupting Solved Pieces:** Be mindful of the pieces you’ve already solved while maneuvering other pieces. Try to find move sequences that minimize disruption.
* **Practice:** The cross is the foundation of the entire solve. Practice it until you can consistently solve it quickly and efficiently. Sub-8 second crosses are achievable with practice.
## Step 2: First Two Layers (F2L)
F2L involves solving the first two layers *simultaneously*. This step can be challenging, but it’s where you can drastically reduce your solve time. We’ll focus on a simplified approach with a few key algorithms and intuitive moves.
The goal is to insert the four corner-edge pairs into their correct slots in the first two layers. Each pair consists of a corner piece and an edge piece that share two colors. The bottom color (white in our example) is on the corner piece, and the edge piece has one of the side colors of that corner piece.
1. **Identify a Pair:** Look for a corner-edge pair in the top layer or the top face that belongs in one of the four slots in the first two layers. The corner piece should have white, and the edge piece should share one of the other two colors on that corner piece.
2. **Position the Corner Piece:** Rotate the bottom layer (D moves) until the slot where the pair belongs is directly below where the corner piece is located on the top layer. The color of the corner piece’s side that isn’t white must correspond to the color of the center piece directly behind the open slot.
3. **Orient the Edge Piece:** Position the edge piece so that it’s either directly above its slot in the top layer or in the UFR or ULF position.
4. **Insertion Algorithms (Simplified):
**
Here are a few common cases and their corresponding algorithms:
* **Case 1: Edge is on top right (UFR) and the white face of the corner is facing front:**
* U R U’ R’ U’ F’ U F
* **Case 2: Edge is on top left (ULF) and the white face of the corner is facing front:**
* U’ L’ U L U F U’ F’
* **Case 3: Edge is on top right (UFR) and the white face of the corner is facing right:**
* R U R’ U’ R U R’
* **Case 4: Edge is on top left (ULF) and the white face of the corner is facing left:**
* L’ U’ L U L’ U’ L
* **If one or both pieces are in the bottom layer but misoriented:** Use any of the above algorithms to remove the pair from the bottom layer and bring both pieces to the top. Then proceed as normal
5. **Intuitive Solutions:** Sometimes, you can insert a pair using simple, intuitive moves. Look for opportunities to directly insert the pair without relying on algorithms. This comes with practice.
6. **Repeat:** Repeat steps 1-5 for all four corner-edge pairs until the first two layers are solved.
**Tips for F2L:**
* **Practice Pair Recognition:** The key to fast F2L is quickly recognizing pairs and their orientations.
* **Learn More Algorithms:** As you improve, explore more F2L algorithms to handle different cases more efficiently.
* **Look Ahead:** While solving one pair, try to spot the next pair and plan your moves accordingly. This reduces pauses between pairs.
* **Don’t Be Afraid to Experiment:** Try different move sequences to see if you can find a more efficient way to insert a pair.
## Step 3: Orient Last Layer (OLL)
OLL focuses on orienting all the pieces in the top layer, meaning getting all the yellow pieces (in our example) facing upwards, without worrying about their position.
We will use a subset of OLL algorithms focusing on common and easy-to-recognize patterns. There are 57 OLL algorithms in total but learning a small subset can get you very far.
1. **Identify the OLL Case:** Look at the top layer and identify the pattern of yellow pieces. This will determine which algorithm to use.
Here are a few frequently encountered OLL cases and their corresponding algorithms:
* **Case 1: The Dot (No yellow pieces on top):**
* F R U R’ U’ F’ U F R U R’ U’ F’
* **Case 2: The Hook (A hook shape formed by yellow pieces on top):**
* F R U R’ U’ F’
* **Case 3: The Bar (A line of yellow pieces on top):**
* F R U R’ U’ F’
* **Case 4: The Headlights (Two adjacent corners are yellow):**
* R U2 R’ U’ R U’ R’
* **Case 5: All edges oriented correctly, only corners need to be:**
* R U R’ U R U2 R’
2. **Execute the Algorithm:** Perform the algorithm corresponding to the OLL case you’ve identified. Make sure you’re holding the cube in the correct orientation before starting the algorithm.
3. **Repeat:** In some cases, you may need to repeat the OLL algorithm multiple times or use a different algorithm to fully orient the top layer.
4. **Common OLL strategies:**
* If you don’t recognize an algorithm, you can often execute one or two known algorithms in sequence to reach a more recognizable state.
**Tips for OLL:**
* **Learn Pattern Recognition:** The faster you can identify the OLL case, the faster you can solve the layer.
* **Practice the Algorithms:** Drill the algorithms until you can execute them smoothly and accurately.
* **Use a Cheat Sheet:** Keep a cheat sheet with the OLL algorithms handy while you’re learning.
## Step 4: Permute Last Layer (PLL)
PLL involves permuting (positioning) the pieces in the top layer without changing their orientation. This is the final step to solving the Rubik’s Cube.
Like OLL, there are many PLL algorithms, but we’ll focus on a subset that’s relatively easy to learn and covers common cases.
1. **Identify the PLL Case:** Examine the top layer to determine which pieces need to be moved and which algorithm to use.
Here are a few essential PLL cases and their corresponding algorithms:
* **Case 1: U-Perm (Adjacent Corners Swap):**
* **Ua Perm:** R U’ R U R U R U’ R’ U’ R2
* **Ub Perm:** R2 U R U R’ U’ R’ U’ R’ U R’
* **Case 2: H-Perm (Edges Swap Across):**
* M2 U M2 U2 M2 U M2
* **Case 3: Z-Perm (Edges Cycle Diagonally):**
* M’ U M2 U M2 U M’ (or, to avoid M moves: R U’ R’ U’ R U R D R’ U’ R D’ R’ U2 R’)
* **Case 4: T-Perm ( Corner and Edge swap):**
* R U R’ U’ R’ F R2 U’ R’ U’ R U R’ F’
2. **Execute the Algorithm:** Perform the algorithm corresponding to the PLL case you’ve identified. Make sure you’re holding the cube in the correct orientation before starting the algorithm.
3. **Cube Solved!:** Once you’ve completed the PLL step, your Rubik’s Cube should be solved!
**Tips for PLL:**
* **Learn to Recognize Patterns:** Practice identifying the PLL cases quickly and accurately.
* **Memorize the Algorithms:** Commit the PLL algorithms to memory for faster solving.
* **Practice Finger Tricks:** Learn efficient finger tricks to execute the algorithms smoothly.
## Advanced Techniques and Optimization
Once you’ve mastered the basics, here are some advanced techniques to further improve your solve times:
* **Full F2L:** Learn more F2L algorithms to handle a wider range of cases.
* **Full OLL/PLL:** Learn all 57 OLL and 21 PLL algorithms for maximum efficiency.
* **Inspection:** Develop a more strategic inspection process to plan your solve in advance.
* **Finger Tricks:** Practice finger tricks to execute algorithms faster and more smoothly.
* **Cross on Bottom:** Learn to solve the cross on the bottom layer directly to save moves.
* **X-Cross:** Solve the cross and the first F2L pair simultaneously for an even faster start.
* **Drills:** Dedicate time to practicing specific algorithms or techniques to improve your muscle memory.
## Resources for Further Learning
* **YouTube:** Channels like J Perm, The Cubicle, and Tingman offer tutorials, tips, and tricks.
* **Speedsolving.com:** A community forum with a wealth of information on speedcubing.
* **Cube Websites:** Websites like The Cubicle and SpeedCubeReview sell cubes and accessories and offer resources.
## Practice, Patience, and Persistence
Solving a Rubik’s Cube takes time, patience, and persistence. Don’t get discouraged if you don’t see results immediately. Keep practicing, keep learning, and you’ll eventually be able to solve the cube consistently and efficiently. Remember the journey of learning is just as rewarding as the solution itself.
This simplified method, focused on understanding and efficiency, will empower you to solve the cube consistently and likely in around 20-40 moves. With further refinement and the incorporation of more advanced techniques, you’ll be well on your way to truly mastering the Rubik’s Cube. Happy cubing!