Pokémon Tier List Generator

A data-driven CLI tool that automatically ranks Pokémon into competitive tiers (S/A/B/C/D) based on base stats, usage data, and configurable meta modifiers.

Why This Exists

I got tired of manually debating tier placements. Stats matter, usage matters, but so do intangibles like "is this thing way too slow to function in modern meta?"

This project exists to:

• Provide a reproducible, data-backed tier list
• Make tier thresholds configurable instead of arbitrary
• Allow experimentation with different scoring philosophies
• Serve as a foundation for more complex ranking systems

It's not meant to replace human judgment entirely, but it gives you a defensible starting point.

How Scoring Works

Each Pokémon gets a score based on three components:

1. Base Stat Score

A weighted sum of all six stats. Offensive stats and Speed are slightly favored because they tend to matter more in competitive play:

Stat	Weight
HP	1.0
Attack	1.15
Defense	0.9
Sp. Attack	1.15
Sp. Defense	0.9
Speed	1.25

These weights live in config/scoring.config.ts. Tweak them if you disagree.

2. Usage Score

Based on competitive usage data (usage % and win rate). Higher usage = we're more confident the Pokémon is actually good in practice.

• Usage is normalized relative to the most-used Pokémon
• Win rate provides a small bonus/penalty centered around 50%
• Pokémon with no usage data get a neutral score (not punished)

3. Meta Modifiers

Adjustments for things pure stats don't capture:

• Glass Cannon Penalty (-8%): High offense + low bulk = inconsistent
• Very Slow Penalty (-12%): Speed < 50 is a real liability
• Legendary Soft Cap (-5%): Keeps the list interesting, not a ban

All modifiers are in rules/modifiers.rules.ts. Easy to add your own.

Tier Thresholds

Tiers are assigned based on percentile rankings:

Tier	Percentile Range
S	Top 10%
A	70-90th
B	45-70th
C	20-45th
D	Bottom 20%

Edit config/tiers.config.ts to rebalance.

Quick Start

# Install dependencies
npm install

# Generate the tier list
npm run generate

# Check the output
cat output/tierlist.json

How to Tweak Tiers

Change stat weights

Edit config/scoring.config.ts:

statWeights: {
  speed: 1.5,  // Make speed even more important
  defense: 1.0,  // Value bulk more
  // ...
}

Change tier thresholds

Edit config/tiers.config.ts:

thresholds: [
  { tier: 'S', minPercentile: 95 },  // More exclusive S tier
  // ...
]

Add/remove modifiers

Edit rules/modifiers.rules.ts and add to activeModifiers array.

How to Add New Pokémon

1. Add entry to data/pokemon.json:

{
  "id": 1000,
  "name": "NewMon",
  "types": ["Dragon", "Steel"],
  "baseStats": {
    "hp": 100,
    "attack": 120,
    "defense": 90,
    "spAttack": 80,
    "spDefense": 85,
    "speed": 95
  }
}

2. Optionally add usage data to data/usage.json:

"NewMon": {
  "usagePercent": 5.5,
  "winRate": 51.0
}

3. Run npm run generate

Project Structure

pokemon-tierlist/
├── data/           # JSON datasets
├── rules/          # Scoring rule implementations
├── engine/         # Core scoring & tier assignment logic
├── config/         # Weights and thresholds
├── utils/          # Helper functions
├── scripts/        # CLI entry point
└── output/         # Generated tier list

Future Ideas (TODO)

• Support for multiple formats (OU, UU, VGC)
• Type effectiveness integration
• Ability/movepool scoring
• Web UI for interactive tier list editing
• Export to image/markdown
• Historical tier tracking over time

Requirements

• Node.js 18+
• npm or yarn

License

MIT - do whatever you want with it.