MTGA Draft Helper

Assist users during MTG Arena drafts by combining 17Lands statistical data with real-time Arena log parsing.

Core Workflow

1. Acquire card data — Fetch card ratings and color win rates from the 17Lands API. See references/17lands-api.md.
2. Read draft state — Parse the Arena Player.log to detect the active draft, current pack/pick, and taken cards. See references/arena-log-parsing.md.
3. Evaluate picks — Use win-rate metrics (GIHWR, OHWR, IWD, ALSA, etc.) and color signals to recommend the best pick. See references/card-evaluation.md.
4. Show card images — Display Scryfall card images from URLs stored in the dataset.
5. Suggest a deck — When the draft is complete (all picks made), build an optimal 40-card deck from the pool. See references/deck-building.md.

Live Draft Tracking (Active Draft Mode)

To assist during a live draft in progress, the agent monitors the Arena log in real time. Full details in references/live-draft-tracking.md.

Quick Start

1. Start watcher — Run live_watcher.py (from the reference) as a background process. It tails Player.log and emits JSON-line events to stdout.
2. Poll for events — Periodically check the background terminal output for new lines.
3. React to each event:
   • draft_start → fetch 17Lands data for the detected set, load set guide.
   • pack → resolve card IDs, evaluate, present ranked pick suggestion with card images.
   • pick_made → record the pick, update colours and curve, confirm to user.
4. Draft complete (42 picks) → auto-build a 40-card deck and present it.

Fallback: Manual Poll

If a background watcher is not available, run this on demand when the user asks:

Get-Content "$env:LOCALAPPDATA\Low\Wizards Of The Coast\MTGA\Player.log" -Tail 200 |
  Select-String "Draft\.Notify|Event_Join|Event_PlayerDraftMakePick|BotDraft_DraftStatus|CardsInPack"

Parse the output for the latest pack/pick data and respond with a suggestion.

Quick Reference

17Lands Card Ratings URL

https://www.17lands.com/card_ratings/data?expansion={SET}&format={FORMAT}&start_date={START}&end_date={END}

Optional: &user_group={top|middle|bottom}, &colors={WU|BG|...}

17Lands Color Ratings URL

https://www.17lands.com/color_ratings/data?expansion={SET}&event_type={FORMAT}&start_date={START}&end_date={END}&combine_splash=true

Card Image URLs

Each card's dataset entry contains an image array with Scryfall URLs:

https://cards.scryfall.io/large/front/{hash}.jpg

For split/DFC cards, a second URL may be present for the back face.

Arena Player.log Location

Key Draft Detection Strings in the Log

Key Data Fields

Draft Suggestion Prompt Template

When making pick suggestions, provide for each pack card:

{Name} | Colors: {W/U/B/R/G} | CMC: {N} | Mana Cost: {cost} | Rarity: {R} | Types: {types} | GIH WR: {X.X}%

Recommend the pick considering:

1. Raw GIHWR (higher is better, >56% is strong, >60% is a bomb)
2. Color alignment with already-drafted cards
3. Mana curve needs (creature distribution across CMC slots)
4. Archetype synergies for the set
5. Wheel probability (cards with high ALSA may come back)

Deck Building Summary

After all picks, build a 40-card deck:

• Target ~17 lands, ~15 creatures, ~8 non-creature spells
• Identify the 2 strongest colors from the pool using color affinity (sum of above-average GIHWR per color)
• Sort cards by GIHWR within the chosen colors, fill creature curve first, then add non-creatures
• Calculate land distribution proportional to mana symbols in the deck
• Output in Arena-importable format: {count} {Card Name}

Detailed References

• 17Lands API details & data schema: references/17lands-api.md
• Arena log parsing procedures: references/arena-log-parsing.md
• Card evaluation methodology: references/card-evaluation.md
• Deck building algorithm: references/deck-building.md
• Live draft tracking (active mode): references/live-draft-tracking.md

Set-Specific Guides

• Lorwyn Eclipsed (ECL): references/ecl-lorwyn-eclipsed.md — Archetype tier list, top commons/uncommons, pick order, card ratings, and draft strategy tips. Sources: Draft Guide, Set Review, Pick Order.
• Through the Omenpaths / Spider-Man (OM1): references/om1-through-the-omenpaths.md — Archetype tier list (GW/UB best, red weak), top commons/uncommons, Pick-Two draft strategy, color identity breakdown, and format tips. Source: Draft Guide.