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 Arceus (Poison)'s top six counters needs 2.55 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.08 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 11:45. No level in this range makes it soloable with a prepared party.

Arceus (Poison) · Tier 5

poison

Weak to

groundpsychic

Boss CP: 49,286
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 Arceus (Poison) 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	4(3.48)	4(3.85)	5(4.82)	17:43	6.0
Level 25	3(2.75)	4(3.19)	4(3.95)	14:40	6.0
Level 30	3(2.49)	3(2.77)	4(3.47)	12:44	6.0
Level 35	3(2.40)	3(2.67)	4(3.25)	12:17	5.9
Level 40	3(2.33)	3(2.55)	4(3.08)	11:45	5.9
Level 45	3(2.26)	3(2.47)	3(2.93)	11:22	5.9
Level 50	3(2.08)	3(2.40)	3(2.82)	11:01	5.8

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

Mewtwo2.33

A prepared party

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

3 trainers at level 40

Mewtwo2.33
Hoopa (Unbound)2.45
Necrozma (Dusk Mane)2.58
Landorus (Therian)2.62
Necrozma (Dawn Wings)2.59
Lunala2.75

A mixed local group

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

4 trainers at level 40

Zamazenta (Crowned Shield)2.98
Latios3.02
Alakazam3.03
Eternatus2.98
Espeon3.06
Azelf3.10

The party these numbers assume

1. Mewtwo

Psycho Cut + Psystrike

2. Hoopa (Unbound)

Confusion + Psychic

3. Necrozma (Dusk Mane)

Psycho Cut + Sunsteel Strike

4. Landorus (Therian)

Mud Shot + Sandsear Storm

5. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

6. Lunala

Confusion + Psychic

See the full ranked counter list for Arceus (Poison) · 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.