Chessbook is the fastest way to build a bulletproof opening repertoire. Key features: • Create a custom repertoire • Train with spaced repetition • Find gaps automatically • Avoid obscure moves • Handle transpositions • Find mistakes in your online games • Learn from model games in the openings you play • Fast & modern interface “A great free way to build your opening repertoire ... really smooth”—FM Nate Solon FIND THE GAPS IN YOUR REPERTOIRE BEFORE YOUR OPPONENTS DO Chessbook calculates you