Deck Comparison

The Deck Comparison page (/deck-comparison) generates structured AI prompts for comparing two Commander decklists side by side. It lives alongside the Deck Analysis page in the Deck Tools tabs.

Step 1 — Deck Setup

Paste two decklists (Moxfield / Archidekt URL or Moxfield, Archidekt, or MTG Arena export text) and select a Commander Bracket for each deck. Optionally name each deck — the service falls back to the commander name if left blank.

Step 2 — Generate Comparison Packet

The service builds a comparison context document with bracket definitions, role counts (ramp, draw, interaction, wipes, recursion, closing power), mana curves, color identity, category overlap, and combo gaps. It generates a structured comparison prompt with sections for task, rules, comparison axes, output format, deck sections, and comparison context. The prompt instructs your AI to produce both a human-readable comparison and a fenced json block matching a deck_comparison schema. A follow-up prompt is also generated for iterative refinement.

Comparison axes include: commander role and game plan, speed and setup tempo, ramp, draw, spot interaction, sweepers, recursion, closing power (including combos), resilience, consistency, mana stability, commander dependence, table fit, major overlap/differences, and five concrete cards or packages that best explain the gap.

Step 3 — Review Results

Paste your AI's JSON response back into the form. The page parses the deck_comparison JSON and renders a formatted view with:

  • Game plans and bracket labels for each deck
  • Strengths and weaknesses per deck
  • Key combos per deck
  • Verdict panel: speed, resilience, interaction, mana consistency, closing power, and combo comparisons
  • Shared themes and major differences
  • Key gap cards or packages
  • Recommended-for notes per deck
  • Confidence notes (when your AI flags uncertainty)

If you continue asking follow-up questions in the same AI conversation, use the follow-up prompt saved alongside the initial comparison to have your AI revise the readable comparison and regenerate the full deck_comparison JSON block.

If your AI splits the answer or says it's "too long"

If your AI breaks the reply into parts or offers to "continue," reply: "Output only the complete deck_comparison JSON in a single response — skip the prose, one short sentence per justification." (The same tip is shown on the page beside the generated prompt.) Don't paste a partial into Step 3 — the page needs one complete deck_comparison object and can't merge parts. Get the whole block in your AI first, then paste once.

Artifact saving

Use Download comparison session (.zip) in the sticky bar at the top of the page (always available, regardless of step) or in the Step 3 results panel to save the current artifacts locally.

The zip can contain: 00-comparison-input-summary.txt, 10-deck-a-list.txt, 11-deck-b-list.txt, 12-deck-a-combos.txt, 13-deck-b-combos.txt, 20-comparison-context.txt, 30-comparison-prompt.txt, 31-comparison-schema.json, 32-comparison-follow-up-prompt.txt, and 40-deck-comparison-response.json.

Use Resume from a saved session (.zip) at the top of the page to upload the same zip later. Re-import only reads 40-deck-comparison-response.json; the other files remain in the archive for your records.