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 Chinchou's top six counters needs 1.92 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.23 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:50. No level in this range makes it soloable with a prepared party. A duo works from level 35.

Chinchou · Elite

waterelectric

Weak to

groundgrass

Boss CP: 18,109
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 Chinchou 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(2.44)	3(2.66)	4(3.14)	12:15	5.8
Level 25	3(2.14)	3(2.33)	3(2.72)	10:43	5.4
Level 30	2(1.93)	3(2.10)	3(2.43)	9:39	5.0
Level 35	2(1.81)	2(1.99)	3(2.33)	9:10	4.9
Level 40	2(1.75)	2(1.92)	3(2.23)	8:50	4.6
Level 45	2(1.69)	2(1.85)	3(2.15)	8:31	4.5
Level 50	2(1.62)	2(1.79)	3(2.08)	8:13	4.4

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

Kartana1.75

A prepared party

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

2 trainers at level 40

Kartana1.75
Landorus (Therian)1.81
Shaymin (Sky)1.90
Zarude2.02
Eternatus2.01
Groudon2.03

A mixed local group

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

3 trainers at level 40

Breloom2.18
Garchomp2.17
Tapu Bulu2.18
Decidueye2.19
Sceptile2.20
Mamoswine2.18

The party these numbers assume

1. Kartana

Razor Leaf + Leaf Blade

2. Landorus (Therian)

Mud Shot + Sandsear Storm

3. Shaymin (Sky)

Magical Leaf + Grass Knot

4. Zarude

Vine Whip + Power Whip

5. Eternatus

Poison Jab + Dynamax Cannon

6. Groudon

Mud Shot + Precipice Blades

See the full ranked counter list for Chinchou · 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.