Schools of Fish & Geometric Patterns - Volume Two

Edition: 2026
Published: November 20, 2025
Part of Series: Unlocking Sudoku: The Art of Seeing the Logic

Buy on Amazon

Overview

Tired of Being Stuck? Guessing? Let’s Fix That.

Let’s be honest: we’ve all been there, staring at a Sudoku grid, totally stuck. It’s the most frustrating part of Sudoku. You know there’s a logical path, but you can’t see it. The tips you find online are confusing, incomplete, and, if they work at all, they work only for certain outlying circumstances. To solve the Sudoku puzzles, you don’t need shortcuts; you need to understand the logic.

Updated Annually. This guide is always up to date. Each year, we publish an updated edition with more techniques, more examples, and anything we see that will make the book a better tool for the Sudoku community. You can trust that you’re always learning the latest and most effective strategies.

Through the series, you’ll learn what to expect when facing a puzzle that has you perplexed, understand the situations you will encounter when solving Sudoku puzzles, and implement battle-tested solving techniques that will push through the tough spots.

If you are ready to stop guessing and start solving, this is the series you’ve been waiting for. Take the first step and add Volume Two to your cart today.

About this book

Volume Two – Schools of Fish and Geometric Patterns (This Book)

This book, containing 280 pages, teaches you to see the grid in a new way by mastering X-Wings, Swordfish, Jellyfish, Skyscrapers, Two-String Kites, Y-Wings, and more.

We know that mastery comes from practice, which is why every one of the technique chapters includes:

Comprehensive Instruction: Clear, concise, and thorough explanations.
Real-World Examples: See the logic in action on large, clear grids.
Post-Chapter FAQs: Get answers to the what-if questions before you even have to ask.
Post-Chapter Assessment Quizzes: A feature unique to this series. Gauge your knowledge and solidify your skills before moving on.

Volume Two – Schools of Fish and Geometric Patterns (This Book) contains:

Part 1: Schools of Fish: Hooking High-Value Eliminations
- CH 1: Learning the Language that Shapes Deduction
- CH 2: An Introduction to Fish Patterns
- CH 3: How to Use the X-Wing on Rows and Columns
- CH 4: Using Fins and Sashimi on an Imperfect X-Wing
- CH 5: Using a 3×3 Pattern to Catch a Swordfish
- CH 6: Using Fins and Sashimi to Save a Swordfish
- CH 7: How to Use Jellyfish to Secure Eliminations
- CH 8: Saving a Jellyfish Using Fins and Sashimi
- CH 9: Higher Order Fish: Little Fish vs. Big Fish

Part 2: Advanced Patterns: The Geometry of the Grid
- CH 10: Using Skyscrapers to Topple Candidates
- CH 11: Using a Crane to Force Timely Eliminations
- CH 12: Using a Two-String Kite to Unlock the Grid
- CH 13: Recognizing the Power of an Empty Rectangle
- CH 14: Using Bi-value Cells to Find a Y-Wing
- CH 15: Extending XY Logic with the XYZ-Wing

Why you'll love this book

Unlocking Sudoku is the most effective and comprehensive Sudoku study guide ever written; a game-changing, four-volume, comprehensive guide that you’ve been waiting for, and Online support is available.

Unlocking Sudoku is not just a book; it’s a complete, four-volume education in logical deduction. We spent thousands of hours deconstructing puzzles to create a groundbreaking curriculum that meets the game on its own terms, patiently teaching every concept needed to go from beginner to grandmaster. With this series, you can be confident that you’re getting a comprehensive education in Sudoku.

A Complete Learning System that includes online access to community support.

Online Support Access: We realize that sometimes you get stuck. You may not see that Swordfish or X-Wing. That’s why we invite you to visit our community site, which we launched, where you can get answers when you’re stuck at no extra charge. Our online support is here to ensure you never feel alone in your Sudoku journey.

Designed for Comfort: Full-size 8.5″ x 11″ format with large print. Large examples.

Each volume, available separately, takes you seamlessly to the next level of solving.

Where to start

Each volume, available separately, takes you seamlessly to the next level of solving.

Volume One – Core Principles & Foundational Techniques (Available Separately): This is where you build the foundation. We’ll guide you through grid architecture, candidate notation, and the core techniques that solve the majority of puzzles: Naked & Hidden Singles, Locked Candidates, Naked Pairs, Triples, and Quads.

Volume Two – Schools of Fish & Geometric Patterns (This Book): Learn to see the grid in a new way by mastering X-Wings, Swordfish, Jellyfish, Skyscrapers, Two-String Kites, Y-Wings, and more.

Volume Three – Advanced Chains & Grandmaster Theory (Available Separately): Follow the logic of cause and effect with Simple Coloring, XY-Chains, Almost Locked Sets, AICs, and other grandmaster tools.

Volume Four – Uniqueness, Expert Theory & Last Resorts (Available Separately): Master the unwritten rules of Uniqueness, which are advanced solving strategies that rely on unique solutions (Deadly Patterns, BUG+1), and the ultimate expert strategies like Forcing Chains, and Bowman’s Bingo.

Features and Specs

Book features

Each book contains large, easy-to-read, and well-explained examples. One full page for each real-world example.
End-of-chapter assessment quizzes help confirm your understanding of the solving techniques.
Four-volume series, each progressively teaches you how to solve puzzles using proven logic-based techniques.
Online support is available at our community support site.
We bet you have friends who play Sudoku, too. This series is a perfect gift.

Book details

There are no Sudoku puzzles in this series to solve. This four-volume series is instructional, not a puzzle book.
Each volume is color-coded. This book is Volume Two (Olive color).
Designed for dedicated learners, this series offers a deep, rewarding dive into advanced logic, making it ideal for teens and adults.
Wider inside margins make it easier to read and to view example puzzles.
The book is full-sized, 8.5 x 11 inches (21.59 x 27.94 cm), and is printed on white paper.
280 pages. More than 1000 pages across the series.
Designed, created, and printed in the USA.

Get it fast

To ensure the highest quality and most reliable service, all Unlocking Sudoku books are printed, sold, and distributed exclusively by Amazon. This allows for consistent quality, fast, trusted shipping, and a secure shopping experience.