Open Coaching Format (OCF)

An open standard for representing team-sport coaching diagrams, drill animations, and playbooks as structured data — for invasion team sports, basketball first.

What is OCF?

The Open Coaching Format is a JSON-based standard for encoding team-sport coaching content — drills, plays, playbooks, and animated diagrams — in a structured, interoperable format. It targets invasion team sports (basketball, soccer, handball, hockey, futsal), with basketball fully defined first and the others reserved with provisional vocabularies.

No open standard for this currently exists. All major coaching tools (FIBA Europe Coaching App, FastDraw, Sportplan.net) use proprietary formats with image-only export. OCF changes that.

Key Features

• 🏀 Basketball-first, sport-agnostic by design — v1 covers basketball (FIBA, NBA, NCAA, NFHS); the architecture supports extension to other sports
• 📐 Real-world coordinates — meters (FIBA) or feet (NBA/NCAA), origin at midcourt center
• 🗺️ Named court positions — top_of_the_key, left_elbow, inbound.baseline_left — grounded in official ruleset geometry
• 🎬 Semantic actions — frames describe what players do (move, cut, screen, defend, dribble, pass, shoot, rebound, pickup) rather than raw geometric lines
• 🏐 Automatic ball possession — a top-level balls[] array (carried_by / at / dead) supports multiple balls; possession transfers are inferred from pass and pickup actions
• 🔀 Hybrid frames — explicit start_state / end_state anchors combined with action sequences; outcome branches (make / miss / …) model continuum drills
• ✏️ Progressive detail — only player + type are required per action; variants, tags, and timing are all optional, so coaches can sketch quickly or annotate fully
• 🤖 LLM-friendly — structured enough for text-to-diagram generation
• ♿ Accessibility — color scheme with WCAG guidance
• 🔄 FIBA import path — coordinate mapping from the FIBA Europe internal format

Quick Example

{
  "court": { "ruleset": "fiba", "type": "half_court" },
  "entities": [
    { "type": "offense", "nr": 1, "x": -3.0, "y": 6.0 },
    { "type": "offense", "nr": 2, "x": 3.0, "y": 6.0 }
  ],
  "balls": [ { "id": "ball_1", "carried_by": "offense_1" } ],
  "frames": [
    {
      "id": "frame_1",
      "actions": [
        { "player": "offense_1", "type": "pass", "to_player": "offense_2" },
        { "player": "offense_1", "type": "cut", "moves": [ { "to": { "named": "basket" } } ] }
      ],
      "end_state": {
        "offense_1": { "named": "basket" },
        "balls": { "ball_1": { "carried_by": "offense_2" } }
      }
    }
  ]
}

Repository Structure

opencoachingformat/
├── schema/
│   └── v1.json                  # JSON Schema Draft-7 (canonical)
├── docs/
│   └── specification-v1.adoc   # Full specification (AsciiDoc)
├── examples/
│   ├── pick-and-roll.ocf.json
│   ├── 3-man-weave.ocf.json
│   ├── transition-3v2.ocf.json
│   ├── quick-mode.ocf.json      # Minimal/quick-mode example
│   └── invalid/                 # Negative test fixtures (schema-invalid)
├── scripts/
│   └── check-invalid.mjs        # Test harness for negative fixtures
├── package.json                 # Dev dependencies and test scripts
├── rfcs/
│   └── 0001-initial-standard.md
└── .github/
    ├── ISSUE_TEMPLATE/
    └── workflows/

Specification

→ Full Specification (AsciiDoc) → JSON Schema v1

Using the schema from npm

npm install @opencoachingformat/spec

import schema from "@opencoachingformat/spec/schema/v1.json" with { type: "json" };

The package ships only schema/v1.json — no runtime code, no dependencies.

Coordinate System

x: −max … 0 … +max   (viewer's left → center → viewer's right)
y: −max … 0 … +max   (defense basket → midline → offense basket)

Units are real-world: meters for FIBA, feet for NBA/NCAA/NFHS.

Supported Rulesets

| Ruleset | Unit | Court (L × W) | |---------|------|-----------------| | fiba | m | 28.0 × 15.0 m | | nba | ft | 94.0 × 50.0 ft | | ncaa | ft | 94.0 × 50.0 ft | | nfhs | ft | 84.0 × 50.0 ft | | custom| * | user-defined |

Implementations

| Project | Type | npm | Status | |---------|------|-----|--------| | ocf-validator | Reference validator (TypeScript + Python) | @opencoachingformat/validator | ✅ Available | | ocf-renderer | Three.js renderer (tactical print mode) | @opencoachingformat/renderer | 🚧 In development | | ocf-editor | Web editor + viewer | — | 📋 Planned |

Built something with OCF? Open a PR to add it here.

Roadmap

This repository defines the schema and standard. Companion projects (separate repos):

1. Validator ✅ — semantic rules JSON Schema can't express: ball-possession consistency (only the carrier may pass/shoot/dribble), branch target integrity, and end_state agreement with action endpoints.
2. Renderer 🚧 — Three.js-based renderer; v1 renders static tactical-print diagrams from OCF JSON (FIBA half/full court). Animation mode planned next.
3. Editor 📋 — visual authoring on top of the renderer.

End goal: generate drills and set plays from natural language (LLM) and render them directly, plus video overlay for practice analysis and video → play extraction.

Contributing

We welcome contributions from coaches, developers, and sports scientists.

See CONTRIBUTING.md for how to:

• Report issues or request features
• Propose changes via the RFC process
• Submit pull requests

License

The Open Coaching Format specification and schema are licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).

You are free to use, share, and adapt the standard — including in commercial products — as long as you give appropriate credit.

Acknowledgements

OCF v1 is informed by reverse-engineering analysis of the FIBA Europe Coaching Website drawing tool, and draws on publicly available ruleset documentation from FIBA, NBA, NCAA, and NFHS.