Goldfish Testing Your Decks

Learn how to use Icarian’s goldfish simulator to test your Commander deck’s consistency and performance.

What Is Goldfishing?

Goldfishing is playing Magic “against no opponent” to test your deck:

• Draw opening hands
• Simulate turns
• Test mana curve
• Check consistency
• Identify problems

It’s called “goldfishing” because a goldfish doesn’t interact - you’re just testing your own deck.

Why Goldfish Test?

Goldfish testing helps you:

1. Test mana curve - See if you can cast spells on curve
2. Evaluate land count - Determine if you have enough/too many lands
3. Find dead hands - Identify problematic opening hands
4. Test ramp - See how quickly you can play your commander
5. Spot clunky draws - Find turns where you have nothing to play

Starting a Goldfish Session

To goldfish your deck:

1. Open your deck
2. Click Goldfish Test
3. Icarian shuffles your deck (99 cards + commander in command zone)
4. Draw your opening hand (7 cards)
5. Review the hand
6. Keep or mulligan

The Opening Hand

Your opening hand shows:

• 7 random cards from your deck
• Number of lands
• Average mana value (CMC)
• Commander in command zone

Decide whether to keep or mulligan based on: - Land count (typically want 2-4 lands) - Castable spells - Early game plays - Curve of the hand

Mulligans (London Mulligan)

If you don’t like your hand:

1. Click Mulligan
2. All 7 cards go back
3. Draw 7 new cards
4. After looking, put N cards on bottom (where N = number of mulligans)

Example: - First mulligan: Draw 7, put 1 on bottom (6 card hand) - Second mulligan: Draw 7, put 2 on bottom (5 card hand)

Icarian tracks: - Number of mulligans taken - Statistics on mulligan frequency

Simulating Turns

After keeping your opening hand:

1. Click Next Turn
2. Draw a card for the turn
3. See updated hand
4. Review what you can play
5. Continue clicking Next Turn to progress

Icarian tracks: - Current turn number - Cards drawn - Lands drawn per turn - Spells drawn per turn

Commander Availability

The simulator tracks when you can cast your commander:

• Turn First Available - Which turn you have enough mana
• Recast Count - How many times you could recast after commander tax

This helps evaluate: - Whether you have enough mana rocks/ramp - If your mana base supports commander cost - How commander tax affects your deck

Example: - 4-mana commander - Turn 4: Can cast commander (4 lands) - Turn 6: Can recast after commander tax (6 mana for 4+2 tax)

Mana Dorks

Mana dorks (creatures that produce mana) are automatically detected using Scryfall tags and provide accurate mana calculations:

• Auto-play: One mana dork per turn (cheapest castable, after land but before rocks)
• Summoning Sickness: Creatures have summoning sickness and can’t tap the turn they’re played
• Mana Production: Each dork produces 1 mana (standard pattern for most dorks)
• Battlefield Display: Dorks appear in their own section between lands and rocks with blue badges
• Statistics: Tracks total dorks played and mana from dorks

Example Turn Sequence: - Turn 1: Play Forest → 1 mana available - Turn 2: Draw and play Plains, draw and play Llanowar Elves (1 CMC) → 2 mana available (elf has summoning sickness) - Turn 3: Draw and play Mountain → 4 mana available (2 land + 1 elf + 1 land = 4 total) - Elf can now tap for mana (summoning sickness cleared) - Play Arcane Signet (2 CMC) using land + elf mana

Auto-Play Priority: 1. Play one land (if available) 2. Play one mana dork (cheapest castable) 3. Play one mana rock (cheapest castable)

The simulator accurately accounts for summoning sickness, ensuring dorks can’t tap until the turn after they’re played (unless they have haste).

Session Statistics

After goldfishing several turns, view statistics:

Hand Quality

• Average CMC - Converted mana cost of opening hands
• Average Lands - Number of lands in opening hands
• Mulligan Rate - Percentage of hands you mulligan

Turn Progression

• Turns Simulated - How many turns you played
• Lands Drawn - Total lands drawn
• Spells Drawn - Total non-land cards drawn
• Lands Per Turn - Average land draws per turn

Commander Stats

• Turn Available - First turn you could cast commander
• Recast Count - Times you could recast with tax

Interpreting Results

Too Many Mulligans

If you mulligan more than 20-30% of hands: - Problem: Poor mana base or inconsistent curve - Solution: Add more lands, better ramp, or fix mana curve

Can’t Cast Commander

If you can’t cast commander until turn 6+: - Problem: Not enough mana acceleration - Solution: Add mana rocks, ramp spells, or land ramp

Too Many Lands

If you draw lands 50%+ of the time after turn 5: - Problem: Too many lands in deck - Solution: Cut 2-3 lands, add card draw or filtering

High Average CMC

If opening hand average is 4+ mana: - Problem: Curve is too high, hands are clunky - Solution: Add more low-CMC cards (1-2 mana)

Low Average CMC

If opening hand average is below 2 mana: - Problem: Too many cheap cards, not enough powerful plays - Solution: Add higher-impact cards, remove filler

Goldfish Session History

View past goldfish sessions:

1. Open your deck
2. Click Goldfish History
3. See all previous sessions with statistics

This helps track: - How deck changes affect consistency - Whether fixes improved performance - Long-term average statistics

Limitations of Goldfishing

Goldfish testing doesn’t simulate:

• Opponent interaction (removal, counterspells)
• Multiplayer politics
• Combat scenarios
• Board state complexity

Use goldfish testing for: - ✓ Mana curve evaluation - ✓ Consistency testing - ✓ Opening hand quality - ✓ Commander availability

Use playtesting (real games) for: - ✓ Interaction with opponents - ✓ Board state management - ✓ Political decisions - ✓ Sideboard decisions

Best Practices

1. Run multiple sessions - Test at least 10 opening hands
2. Track changes - Goldfish before and after deck edits
3. Simulate realistic keeps - Mulligan hands you’d actually mulligan in a game
4. Note patterns - Look for recurring problems (always flooding, always missing lands)
5. Compare to ideal - Your deck should cast commander by turn 4-5 and have plays every turn

Example: Identifying Issues

Session Results

• 10 opening hands tested
• 4 mulligans (40% mulligan rate) ⚠️
• Average 2.3 lands in opening hand ✓
• Commander available turn 6 on average ⚠️
• Average CMC: 4.2 ⚠️

Diagnosis

• High mulligan rate → Inconsistent hands
• Commander late → Not enough ramp
• High CMC → Curve too high

Fixes

1. Add 3 mana rocks (Sol Ring, Arcane Signet, Fellwar Stone)
2. Cut 3 high-CMC cards (6+ mana)
3. Add 2 more lands

After fixes, re-goldfish to verify improvement!