Agent skill

Algo Rank Elo

by asgard-ai-platform in asgard-ai-platform/skills

Implement Elo rating system to rank items or players from pairwise comparison outcomes.

MITAuto-check passed

Install Algo Rank Elo

skills CLI
$ npx skills add asgard-ai-platform/skills --skill algo-rank-elo -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install asgard-ai-platform/skills algo-rank-elo --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/asgard-ai-platform/skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/algo-rank-elo .claude/skills/algo-rank-elo && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
algo-rank-elo
GitHub stars
242
Token cost
~1.1k tokens
SKILL.md length
417 words
Files
5 (incl. scripts, references)
Skills in repo
207
Repo updated
First seen
Licence
MIT

At a glance

Implement Elo rating system to rank items or players from pairwise comparison outcomes.

  • Works in 4 steps: Input Validation → Core Algorithm → Verification → …
  • The user needs to rank items from head-to-head matchups
  • SKILL.md covers Overview, When to Use, Algorithm and Output Format, plus 4 more sections
  • Runs Python scripts from its folder; calls python

What it does

Algo Rank Elo is an agent skill from asgard-ai-platform/skills. Implement Elo rating system to rank items or players from pairwise comparison outcomes. Use this skill when the user needs to rank items from head-to-head matchups, build a competitive rating system, or evaluate relative quality from comparison data — even if they say 'player rating', 'ranking from comparisons', or 'competitive scoring system'.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 7 other files, including scripts and reference files (for example `examples/sample_input.json`, `references/bradley-terry.md` and `references/variable-k.md`).

The repository describes itself as: 301 open-source coding agent skills across 22 domains — methodology, judgment & gotchas packaged as Claude Agent Skills for the Asgard AI Platform. The licence is MIT.

When your agent uses it

  • The user needs to rank items from head-to-head matchups
  • Build a competitive rating system
  • Evaluate relative quality from comparison data — even if they say player rating
  • Ranking from comparisons

Example prompts

  • “player rating”
  • “ranking from comparisons”
  • “competitive scoring system”
  • “/algo-rank-elo”

Requirements

  • Python 3

Workflow steps

4 steps, taken from the step headings in SKILL.md.

  1. Input Validation
  2. Core Algorithm
  3. Verification
  4. Output

What it can do on your machine

Read from SKILL.md and the folder at commit 4e7f4f8. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Ships 1 file in scripts/ (Python), which the agent can run.

    Shell commands in SKILL.md call:

    • python

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Algo Rank Elo loads about 1.1k tokens when it runs, and up to ~5.2k if it reads all its reference files. Until then it costs about 90 tokens; SKILL.md has 417 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~90
When it runs · the whole SKILL.md, loaded when a task matches
~1.1k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~5.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from asgard-ai-platform/skills at commit 4e7f4f8, republished under its MIT licence (© asgard-ai-platform). 417 words, ~1,053 tokens.

Download SKILL.mdSave it as .claude/skills/algo-rank-elo/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.
name
algo-rank-elo
description
Implement Elo rating system to rank items or players from pairwise comparison outcomes. Use this skill when the user needs to rank items from head-to-head matchups, build a competitive rating system, or evaluate relative quality from comparison data — even if they say 'player rating', 'ranking from comparisons', or 'competitive scoring system'.
metadata.category
WP-44 排名演算法
metadata.tags
ranking, elo, pairwise-comparison, rating-system

Elo Rating System

Overview

Elo assigns numerical ratings that update after each pairwise comparison. Winner gains points, loser loses points. The amount exchanged depends on expected vs actual outcome. Originally for chess, now used for sports, games, and A/B preference testing. Update runs in O(1) per match.

When to Use

Trigger conditions:

  • Ranking items from pairwise comparison data (A vs B outcomes)
  • Building competitive rating systems for games or sports
  • Crowdsourced quality evaluation through pairwise preferences

When NOT to use:

  • When you have absolute scores, not pairwise comparisons (use direct ranking)
  • When team dynamics matter more than individual skill (use TrueSkill)

Algorithm

IRON LAW: Elo Assumes Each Matchup Is Independent and Stationary
Rating changes are based on surprise: beating a higher-rated opponent
gains more points than beating a lower-rated one. K-factor controls
update speed: high K (32) = volatile, fast adaptation. Low K (16) =
stable, slow adaptation. Choose K based on how quickly skill changes.
Phase 1: Input Validation

Initialize all participants at base rating (typically 1500). Collect match results: winner, loser (or draw). Gate: Valid match data, no self-matches.

Phase 2: Core Algorithm
  1. Expected score: E_A = 1 / (1 + 10^((R_B - R_A)/400))
  2. Actual score: S_A = 1 (win), 0.5 (draw), 0 (loss)
  3. Update: R_A_new = R_A + K × (S_A - E_A)
  4. Process all matches sequentially (order matters for sequential Elo)
Phase 3: Verification

Check: total rating points conserved (zero-sum). Rating distribution is reasonable (no extreme values from data errors). Gate: Ratings conserved, top-ranked items pass sanity check.

Phase 4: Output

Return sorted ratings with confidence indicators.

Output Format

json
{
  "ratings": [{"id": "player_A", "rating": 1720, "matches": 50, "wins": 35, "losses": 15}],
  "metadata": {"k_factor": 32, "initial_rating": 1500, "total_matches": 500}
}

Examples

Sample I/O

Input: Player A (1500) beats Player B (1500), K=32 Expected: E_A = 0.5, S_A = 1. R_A_new = 1500 + 32×(1-0.5) = 1516. R_B_new = 1484.

Edge Cases
InputExpectedWhy
1500 beats 2000Large rating gain (~29 pts at K=32)Huge upset, large surprise
2000 beats 1500Small rating gain (~3 pts at K=32)Expected outcome, minimal surprise
Draw between equalsNo changeExpected outcome exactly matches actual
Show full SKILL.md (147 more words)Show less

Gotchas

  • K-factor selection: Too high = ratings oscillate. Too low = slow to reflect actual skill changes. Use variable K: higher for new participants, lower for established ones.
  • Order dependence: Sequential Elo ratings depend on match processing order. For batch processing, use iterative Elo or Bradley-Terry model.
  • Inflation/deflation: In open systems where participants enter/leave, average rating can drift. Use rating floors or periodic calibration.
  • Not designed for teams: Standard Elo is for 1v1. For teams, average team ratings or use TrueSkill which models individual contribution within teams.
  • Rating ≠ win probability: A 200-point rating gap implies ~76% expected win rate, but actual outcomes depend on context, form, and luck.

Scripts

ScriptDescriptionUsage
scripts/elo.pyUpdate Elo ratings (single match or batch) with zero-sum verificationpython scripts/elo.py --help

Run python scripts/elo.py --verify to execute built-in sanity tests.

References

  • For Bradley-Terry model (batch Elo), see references/bradley-terry.md
  • For variable K-factor strategies, see references/variable-k.md

© asgard-ai-platform, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files (scripts, references) in algo-rank-elo of asgard-ai-platform/skills.

  • SKILL.md
  • examples/sample_input.json
  • references/bradley-terry.md
  • references/variable-k.md
  • scripts/elo.py

Open the folder on GitHubat commit 4e7f4f8

Compare with similar skills

Algo Rank Elo next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Algo Rank Elo compared with similar skills
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Algo Rank Elo this skillasgard-ai-platform/skills242—~1.1kAutomated safety check: PassMIT
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Implementsickn33/agentic-awesome-skills47k5 repos~306Automated safety check: PassMIT
Implementcodewhale-hq/Codewhale41k—~190Automated safety check: PassMIT
MCP Implementation Security Reviewgithub/awesome-copilot40k—~5.2kAutomated safety check: PassMIT
Implementing API Key Security Controlsmukul975/Anthropic-Cybersecurity-Skills34k—~4kAutomated safety check: PassApache-2.0

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Questions about Algo Rank Elo

What does Algo Rank Elo do?

Implement Elo rating system to rank items or players from pairwise comparison outcomes. Algo Rank Elo is an agent skill from asgard-ai-platform/skills. Implement Elo rating system to rank items or players from pairwise comparison outcomes.

When should I use Algo Rank Elo?

Algo Rank Elo fits situations like: the user needs to rank items from head-to-head matchups; build a competitive rating system; evaluate relative quality from comparison data — even if they say player rating; ranking from comparisons.

How do I install Algo Rank Elo in Claude Code?

Run `npx skills add asgard-ai-platform/skills --skill algo-rank-elo -a claude-code`. Or copy the skill folder (algo-rank-elo in asgard-ai-platform/skills) into .claude/skills/algo-rank-elo in your project. Claude Code loads it when a task matches its description.

How do I install Algo Rank Elo in Codex?

Run `npx skills add asgard-ai-platform/skills --skill algo-rank-elo -a codex`. Or copy the skill folder (algo-rank-elo in asgard-ai-platform/skills) into .agents/skills/algo-rank-elo in your project. Codex loads it when a task matches its description.

Can I use Algo Rank Elo in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add asgard-ai-platform/skills --skill algo-rank-elo -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/algo-rank-elo, .gemini/skills/algo-rank-elo, .github/skills/algo-rank-elo and .opencode/skills/algo-rank-elo in your project.

What does Algo Rank Elo need to run?

Going by SKILL.md and its folder, Algo Rank Elo needs Python for the scripts in its folder and the command-line tools its instructions call (python). Our summary lists: Python 3.

Does Algo Rank Elo access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Algo Rank Elo safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.

What licence does Algo Rank Elo use?

Algo Rank Elo is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Algo Rank Elo use?

About 1.1k tokens (SKILL.md is roughly 4.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 4.2k tokens, read only when the agent opens those files.

What are the alternatives to Algo Rank Elo?

Skills that share tags, products or a category with Algo Rank Elo: Implementing API Abuse Detection With Rate Limiting (mukul975/Anthropic-Cybersecurity-Skills, 34k stars), Implement (sickn33/agentic-awesome-skills, 47k stars), Implement (codewhale-hq/Codewhale, 41k stars) and MCP Implementation Security Review (github/awesome-copilot, 40k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Algo Rank Elo?

asgard-ai-platform (a GitHub organization) maintains it in asgard-ai-platform/skills, which has 242 GitHub stars. The repository holds 207 skills in this directory. The repository was last updated on June 6, 2026.

Source: asgard-ai-platform/skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.