Calculation mastery, one pattern at a time
Each chapter follows the same rhythm: learn the motif on interactive diagrams, practice it on guided exercises, then prove it in a scored test.
The Pin
Absolute and relative pins — immobilise the defender and win the piece behind.
5 lessons · 5 exercises · 7 test positions
The Skewer
The reverse pin — attack the king or queen and win the piece behind.
5 lessons · 5 exercises · 7 test positions
Trapped Pieces
Restrict, then capture — the piece that has no escape.
5 lessons · 5 exercises · 7 test positions
X-Ray Attack
The long-range beam through the defender — rook, bishop and queen X-rays.
5 lessons · 5 exercises · 7 test positions
Interference
Block the line — cut the communication between defender and target.
5 lessons · 5 exercises · 7 test positions
Zugzwang
The compulsion to move — when any move loses, the position wins itself.
5 lessons · 5 exercises · 7 test positions