The opening book is estimated to contribute an average of 40 Elo points of improvement per year, often providing more of a strength boost than an engine upgrade alone .

Contents & purpose

The (such as version 15q) provide a massive repository of chess theory, including over 33 million positions and nearly 2 million variations . Designed for both elite human preparation and high-level engine play, these books are available in several industry-standard formats:

A great opening book is not a crutch—it’s a library that speaks in variations. Hiarcs 15q spoke clearly, and for the first time, Elena listened.

You can purchase the directly from the Hiarcs website or authorized resellers like ChessCentral or Amazon. Ensure the download link clearly states that the package includes CTG and BIN files—some old versions only offer CTG.

version for the engine to use directly during analysis or play. iOS Devices:

Whether you choose to explore its deep CTG branches in Fritz, load the BIN version in Arena, or simply scroll through the annotated PGN in a weekend study session, you will find lines that are provocative, sound, and – most importantly – .