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 Arctibax's top six counters needs 1.81 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.46 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:19. No level in this range makes it soloable with a prepared party. A duo works from level 35.

Arctibax · Elite

dragonice

Weak to

fightingrocksteeldragonfairy

Boss CP: 31,793
Boss HP: 20,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Arctibax 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(2.33)	3(2.60)	4(3.90)	11:57	5.9
Level 25	3(2.05)	3(2.25)	4(3.18)	10:22	5.8
Level 30	2(1.81)	3(2.01)	3(2.74)	9:15	5.6
Level 35	2(1.77)	2(1.90)	3(2.58)	8:46	5.6
Level 40	2(1.64)	2(1.81)	3(2.46)	8:19	5.4
Level 45	2(1.61)	2(1.77)	3(2.38)	8:09	5.3
Level 50	2(1.58)	2(1.71)	3(2.29)	7:51	5.1

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

Zacian (Crowned Sword)1.64

A prepared party

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

2 trainers at level 40

Zacian (Crowned Sword)1.64
Eternatus1.67
Zamazenta (Crowned Shield)1.74
Necrozma (Dusk Mane)1.77
Keldeo1.95
Dialga (Origin)2.06

A mixed local group

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

3 trainers at level 40

Haxorus2.38
Blaziken2.39
Metagross2.42
Tinkaton2.42
Dragapult2.43
Regidrago2.48

The party these numbers assume

1. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

2. Eternatus

Dragon Tail + Dynamax Cannon

3. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

4. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

5. Keldeo

Low Kick + Secret Sword

6. Dialga (Origin)

Metal Claw + Roar of Time

See the full ranked counter list for Arctibax · 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.