Rank King

A webapp for ranking items along multiple axes through pairwise comparisons, powered by OpenSkill (Plackett-Luce).

Domain

• List — a collection of items to rank (e.g., "Favorite Foods")
• Item — a thing being ranked (e.g., "Pizza", "Sushi", "Tacos")
• Axis — a dimension to rank along (e.g., "Taste", "Value", "Convenience")
• Matchup — a head-to-head comparison of two items on an axis
• Result — the record of who won a matchup
• Rating — the OpenSkill score for an item on an axis, derived from results

A List has Items and Axes. A Matchup presents two Items on an Axis. A Result records the winner. Ratings are derived from Results.

Features

• Create a list by entering items into a text area
• Define one or more axes to rank along
• Pick matchups manually, get random ones, or use suggested matchups (the pair that reduces overall variance the most)
• View ratings per axis
• Publish a public, read-only view of an axis's rankings to share with others

Design decisions

• In-memory storage to start
• No auth to start

Future

• Persistence
• Users and auth
• API
• 2×2 matrix view plotting items across two axes