Group size estimator

How many trainers do I need to invite?

The Estimator is already "trainers of this attacker needed to finish inside the timer", so this page does not invent a number: it reads it off the boss's own ranked counter list for three realistic parties and re-simulates each of them at every level from 20 to 50.

Raid bossTierIVsWeatherFriendshipDodgingShadow attackersMega attackersLegendary attackers

Invite 3 to be safe — 2 if everyone is prepared

At level 40, a party of Melmetal's top six counters needs 1.91 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.37 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:47. No level in this range makes it soloable with a prepared party. A duo works from level 40.

Melmetal · Tier 5

steel

Weak to

fightinggroundfire

Boss CP: 42,260
Boss HP: 15,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Melmetal at each attacker level
Attacker level	Six of the best counter	A prepared party	A mixed local group	Prepared solo time	Faints per timer
Level 20	3(2.49)	3(2.91)	4(3.59)	13:23	6.0
Level 25	3(2.11)	3(2.48)	3(2.97)	11:25	6.0
Level 30	2(1.92)	3(2.14)	3(2.62)	9:51	6.0
Level 35	2(1.77)	3(2.00)	3(2.50)	9:13	6.0
Level 40	2(1.70)	2(1.91)	3(2.37)	8:47	6.0
Level 45	2(1.65)	2(1.83)	3(2.29)	8:26	6.0
Level 50	2(1.61)	2(1.77)	3(2.19)	8:08	6.0

Whole trainers in bold, the raw estimator in brackets — 2.04 means two trainers is right on the line and three is comfortable.

Six of the best counter

Every trainer brings six copies of the single best counter — the theoretical floor.

2 trainers at level 40

Keldeo1.70

A prepared party

Each trainer brings the boss's top six counters, powered up and correctly TM'd.

2 trainers at level 40

Keldeo1.70
Blacephalon1.81
Lucario1.96
Reshiram1.96
Terrakion2.00
Landorus (Therian)2.03

A mixed local group

Ranks 13-24: reasonable but unoptimised parties, which is what a public lobby usually is.

3 trainers at level 40

Urshifu (Rapid Strike)2.27
Marshadow2.35
Emboar2.38
Chandelure2.36
Cinderace2.34
Delphox2.38

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Blacephalon

Incinerate + Mind Blown

3. Lucario

Force Palm + Aura Sphere

4. Reshiram

Fire Fang + Fusion Flare

5. Terrakion

Double Kick + Sacred Sword

6. Landorus (Therian)

Mud Shot + Sandsear Storm

See the full ranked counter list for Melmetal · check a real lobby (win chance, who brings what) · make a share card of the top six

How this is worked out

The boss is ranked once at level 40 with rankCached (the same memoised call /raids makes), then the three bands — rank 1, ranks 1-6, ranks 13-24 — are re-simulated at each attacker level with an 8-run Monte Carlo each. Holding the party fixed and moving only its level is deliberate: it answers "what if my party were level 20" rather than "what would a level-20 player's completely different party be", and it is about ten times cheaper than re-ranking every attacker seven times. The Estimator itself is Pokebattler's definition, time to win including rejoin time divided by the raid timer.