Chess Openings Dataset

1,506 chess openings and defences covering all 500 ECO codes (A00–E99) — free JSON/CSV, CC-BY 4.0.

The structured data behind Chess Openings — a free encyclopedia with a complete guide for every opening in the ECO. Each row is one publishable opening article: move order, strategic ideas for both sides, traps, famous practitioners, history and popularity/difficulty ratings.

Use it to seed opening tables, repertoire apps, chess GUIs, search filters, autocomplete, LLM fine-tuning, research — attribution is the only ask.

Files

File	Rows	Size	Description
data/openings.json	1,506	~1.2 MB	Full dataset, one object per opening
data/openings.csv	1,506	~0.8 MB	Flat CSV (arrays joined with ; )

Dataset composition

• 69 opening families — the top-level systems (Najdorf, Ruy Lopez, King's Indian…), with full strategic write-ups
• 937 named variations — sub-lines grouped under their family
• 500 ECO code entries — one for every code A00–E99

Quick start

JavaScript / TypeScript

const res = await fetch("https://raw.githubusercontent.com/Maahi420/chess-openings-data/main/data/openings.json");
const openings = await res.json();
console.log(openings.filter(o => o.eco.startsWith("B")).length); // 348 semi-open entries

Python

import pandas as pd
df = pd.read_csv("https://raw.githubusercontent.com/Maahi420/chess-openings-data/main/data/openings.csv")
print(df[df.eco == "B90"].to_dict("records"))

Field dictionary

Field	Type	Description
name	string	Full display name ("Sicilian Defence, Najdorf Variation")
kind	family | variation | eco	Article type
eco	string	ECO code, "A00"–"E99"
moves	string	Main line in SAN from the initial position, e.g. "1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6"
side	white | black | either	Side the opening belongs to
style	enum	Aggressive / Positional / Solid / Sharp / Tricky / Universal
tags	string[]	Up to 3 of 25 tags (gambit, hypermodern, fianchetto, trap-heavy…)
popularity	1–5	5 = world-class main line
difficulty	1–5	5 = thickest theory
description	string	What the opening is and why it's played
white_ideas	string	Strategic plans for White (families)
black_ideas	string	Strategic plans for Black (families)
traps	string[]	Named traps with one-line explanations (families)
famous_players	string[]	Notable practitioners (families)
history	string	Short history (families)
url	string	The full guide on chess-openings.sryze.cc

Example

{
  "name": "Sicilian Defence, Najdorf Variation",
  "kind": "family",
  "eco": "B90",
  "moves": "1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6",
  "side": "black",
  "style": "Sharp",
  "tags": ["counter-attacking", "elite-favourite", "tactical"],
  "popularity": 5,
  "difficulty": 5,
  "description": "The Najdorf is chess at its most ferocious...",
  "traps": ["..."],
  "famous_players": ["Bobby Fischer", "Garry Kasparov"],
  "url": "https://chess-openings.sryze.cc/opening/sicilian-defence-najdorf-variation-b90"
}

Why this dataset

• Complete: every ECO code, not a highlights reel
• Rich: strategic ideas and traps per opening, not bare move lists
• Clean: consistent schema, typed fields, machine-readable from day one
• Living: maintained as part of chess-openings.sryze.cc, where every row links to its full interactive guide

License

CC BY 4.0 — free for any use, including commercial, with attribution:

Chess Openings Dataset by chess-openings.sryze.cc/, licensed under CC BY 4.0.

Contact: amysinclaire944@gmail.com — questions, licensing, or corrections welcome.

Used it? A link back to https://chess-openings.sryze.cc/ helps others find the full guides — and do open an issue to say hi. 🤝