Learn the basics free. Practice advanced reasoning with Coaching.
Use the free references to learn the rules, candidate notes, and first forced moves. When you reach an intermediate or advanced pattern, Coaching teaches the full check on fresh grids and lets you make the elimination yourself.
4 free references · 2 Coaching previewsHow to use this library
Build the foundation. Practice the hard part.
The public guides explain beginner checks with worked grids. Advanced previews show what you will learn without revealing the complete proof or answer sequence.
Free beginner references
Complete worked examples for the knowledge every new solver needs.
Included with Coaching
Advanced techniques are learned by doing
These previews describe the skill. The complete proof, near-miss checks, guided exercise, and feedback stay inside Coaching.
Turn the proof into a move
Interactive lessons use fresh boards and ask you to make the next check yourself. Beginner lessons are free; intermediate and advanced lessons are part of Coaching.
Explore interactive lessons →