CIPHER  9
Split Protocol cover
Cipher 9 Sudoku · Vol.04

Split Protocol

Expert Sudoku

150

Puzzles

198

Pages

Expert

Difficulty

About this book

Split Protocol is where technique separates from instinct. Expert-level grids that require advanced solving strategies — X-wings, swordfish, and beyond. If you can finish this book without looking at the solutions, you belong in the top tier.

Perfect for:Adults

Buyer Fit

Who this book is for

  • Sudoku solvers who want a clean paper session
  • Adults who want focused puzzle time
  • Gift buyers looking for a polished puzzle book
  • Experienced solvers ready for a sharper challenge

Volume Identity

What makes this volume different

  • Expert stage in the Cipher 9 Sudoku progression
  • 150 grids sized for this difficulty level
  • One puzzle per page keeps the solving experience clean
  • Checkpoint pages help track progress through the volume

Specifications

Formatpaperback
Pages198
Trim Size8.5 x 11 in
PaperWhite paper
Puzzles150
Puzzle TypeSudoku
DifficultyExpert
LanguageEnglish
ASINB0GXWXQJNV

Inside the Book

Preview the pages

Cover and interior samples from the current book files.

Cover
Title page
Rules
Puzzle page
Checkpoint
Solutions
Sample solution

Series Ladder

Compare volumes in Cipher 9 Sudoku

View series →
Vol.01
First Contact

100 Sudoku Grids — Entry Level

DifficultyBeginner

Puzzles100

StatusAvailable now

Price$10.99

Vol.02
Deep Run

Intermediate Sudoku

DifficultyIntermediate

Puzzles150

StatusAvailable now

Price$12.99

Vol.03
Night Shift

180 Sudoku Grids — Hard

DifficultyHard

Puzzles180

StatusAvailable now

Price$13.99

Vol.04Current
Split Protocol

Expert Sudoku

DifficultyExpert

Puzzles150

StatusAvailable now

Price$13.99

Vol.05
Ghost Grid

Master Level

DifficultyMaster

Puzzles75

StatusAvailable now

Price$11.99

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