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 5 to be safe — 4 if everyone is prepared

At level 40, a party of Articuno's top six counters needs 3.20 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.18 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 15:08. No level in this range makes it soloable with a prepared party.

Articuno · Shadow Tier 5

iceflying

Weak to

rocksteelfireelectric

Boss CP: 40,165
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 Articuno 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(4.29)	5(4.75)	7(6.37)	22:26	6.0
Level 25	4(3.99)	5(4.05)	6(5.40)	19:07	6.0
Level 30	4(3.23)	4(3.50)	5(4.58)	16:31	5.9
Level 35	4(3.19)	4(3.35)	5(4.37)	15:50	5.9
Level 40	4(3.11)	4(3.20)	5(4.18)	15:08	5.9
Level 45	4(3.04)	4(3.11)	4(3.93)	14:40	5.7
Level 50	3(2.93)	3(3.00)	4(3.83)	14:10	5.7

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.

4 trainers at level 40

Zacian (Crowned Sword)3.11

A prepared party

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

4 trainers at level 40

Zacian (Crowned Sword)3.11
Rampardos3.15
Zamazenta (Crowned Shield)3.14
Glimmora3.21
Necrozma (Dusk Mane)3.30
Terrakion3.31

A mixed local group

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

5 trainers at level 40

Aurorus3.86
Blacephalon3.88
Omastar4.10
Lycanroc (Midnight)4.13
Lycanroc (Midday)4.18
Lycanroc (Dusk)4.22

The party these numbers assume

1. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

2. Rampardos

Smack Down + Rock Slide

3. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

4. Glimmora

Rock Throw + Meteor Beam

5. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

6. Terrakion

Smack Down + Rock Slide

See the full ranked counter list for Articuno · 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.