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 4 to be safe — 3 if everyone is prepared

At level 40, a party of Zacian (Crowned Sword)'s top six counters needs 2.91 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.50 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 13:22. No level in this range makes it soloable with a prepared party.

Zacian (Crowned Sword) · Tier 5

fairysteel

Weak to

groundfire

Boss CP: 67,864
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 Zacian (Crowned Sword) 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	5(4.47)	5(4.74)	6(5.60)	21:48	6.0
Level 25	4(3.83)	4(3.96)	5(4.82)	18:13	6.0
Level 30	4(3.23)	4(3.35)	5(4.10)	15:24	6.0
Level 35	3(2.96)	4(3.09)	4(3.76)	14:12	6.0
Level 40	3(2.66)	3(2.91)	4(3.50)	13:22	6.0
Level 45	3(2.55)	3(2.79)	4(3.30)	12:51	6.0
Level 50	3(2.39)	3(2.68)	4(3.08)	12:19	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.

3 trainers at level 40

Reshiram2.66

A prepared party

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

3 trainers at level 40

Reshiram2.66
Blacephalon2.70
Heatran2.81
Groudon3.04
Ho-Oh3.09
Zamazenta (Crowned Shield)3.12

A mixed local group

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

4 trainers at level 40

Delphox3.36
Volcarona3.36
Landorus (Therian)3.34
Moltres3.41
Volcanion3.45
Garchomp3.51

The party these numbers assume

1. Reshiram

Fire Fang + Fusion Flare

2. Blacephalon

Incinerate + Mind Blown

3. Heatran

Fire Spin + Magma Storm

4. Groudon

Mud Shot + Precipice Blades

5. Ho-Oh

Incinerate + Sacred Fire++

6. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

See the full ranked counter list for Zacian (Crowned Sword) · 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.