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 2 to be safe — 2 if everyone is prepared

At level 40, a party of Arctibax's top six counters needs 1.09 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.47 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 5:00. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Arctibax · Tier 5

dragonice

Weak to

fightingrocksteeldragonfairy

Boss CP: 27,534
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 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	2(1.39)	2(1.54)	3(2.18)	7:06	5.8
Level 25	2(1.21)	2(1.33)	2(1.81)	6:08	5.6
Level 30	2(1.10)	2(1.21)	2(1.61)	5:33	5.3
Level 35	2(1.05)	2(1.14)	2(1.53)	5:14	5.1
Level 40	1(1.00)	2(1.09)	2(1.47)	5:00	4.9
Level 45	1(0.96)	2(1.05)	2(1.41)	4:49	4.7
Level 50	1(0.94)	2(1.01)	2(1.36)	4:40	4.5

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.

1 trainer at level 40

Zacian (Crowned Sword)1.00

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)1.00
Eternatus1.00
Zamazenta (Crowned Shield)1.05
Necrozma (Dusk Mane)1.04
Keldeo1.17
Dialga (Origin)1.25

A mixed local group

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

2 trainers at level 40

Haxorus1.40
Blaziken1.41
Tinkaton1.45
Metagross1.45
Regidrago1.46
Dragapult1.47

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.