The Hiarcs 15q Openings Book is a premier chess opening repertoire database, meticulously crafted by the legendary Hiarcs team. Known for powering one of the strongest chess engines in history, Hiarcs has now distilled decades of grandmaster-level opening theory, correspondence chess novelties, and engine-assisted analysis into a single, highly optimized opening book.
This package includes the book in multiple formats – most notably .CTG (for ChessBase/Fritz GUI) and .ABK (for Arena/WinBoard) – ensuring compatibility with virtually every major chess interface. Whether you are an online blitz player, a correspondence specialist, an engine user preparing analysis, or a club player looking to sharpen your repertoire, the Hiarcs 15q book delivers immediate, reliable, and aggressive opening guidance.
We tested the Chess Hiarcs 15q Openings Book against the default Stockfish 17 book and the popular "Don 7.9" free book.
This is unique to Hiarcs. The .hkb file is a semantic map of positional evaluations tied to specific pawn structures. For example, if you reach a French Winawer position with opposite-side castling, the .hkb file injects positional advice directly into the engine’s evaluation bar when used alongside Hiarcs 15q. Chess Hiarcs 15q Openings Book Includes Ctg And...
A. Format Compatibility (CTG) The inclusion of the CTG format is a major selling point.
B. Content & Depth Hiarcs opening books are famously broad.
C. The "Includes..." Component The subject line cuts off with "And...", which usually implies the inclusion of: The Hiarcs 15q Openings Book is a premier
The keyword phrase emphasizes that this book includes CTG and and BIN formats. If you are wondering why that is a selling point, here is the technical breakdown every advanced user needs.
CTG is the proprietary book format for ChessBase and Fritz interfaces. This is the gold standard for professional over-the-board preparation.
The keyword phrase explicitly notes that the Chess Hiarcs 15q Openings Book includes Ctg and other formats. What are those, and why do they matter? We tested the Chess Hiarcs 15q Openings Book
| Book Feature | Hiarcs 15q | Generic Free Book (e.g., Perfect 2023) | Commercial Book (e.g., Powerbook 2024) | |--------------|-------------|----------------------------------------|------------------------------------------| | Position count | 4.5M+ | ~500k–1M | 3M–5M | | Engine-tuned weights | Yes (Hiarcs 15) | Rarely | Yes (various) | | Correspondence novelties | Extensive | Few | Moderate | | .CTG included | ✅ | Sometimes | ✅ | | .ABK included | ✅ | Rare | ❌ usually sold separately | | Anti-computer lines | Yes | No | Partial | | Price range | Mid-tier | Free | High-tier ($100+) |
Verdict: Hiarcs 15q sits in the best value category – near the quality of premium books but at a fraction of the cost, plus the unique
.ABKinclusion.