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 Gossifleur's top six counters needs 1.69 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.08 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 7:48. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Gossifleur · Elite

grass

Weak to

flyingpoisonbugfireice

Boss CP: 13,113
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 Gossifleur 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(2.30)	3(2.34)	3(2.88)	10:46	4.7
Level 25	2(1.92)	3(2.05)	3(2.53)	9:25	4.0
Level 30	2(1.70)	2(1.84)	3(2.28)	8:27	3.5
Level 35	2(1.64)	2(1.77)	3(2.17)	8:08	3.2
Level 40	2(1.56)	2(1.69)	3(2.08)	7:48	3.0
Level 45	2(1.51)	2(1.64)	3(2.02)	7:33	2.8
Level 50	2(1.46)	2(1.59)	2(1.96)	7:19	2.7

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.

2 trainers at level 40

Blacephalon1.56

A prepared party

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

2 trainers at level 40

Blacephalon1.56
Kyurem (White)1.62
Rayquaza1.67
Eternatus1.73
Reshiram1.79
Kyurem (Black)1.80

A mixed local group

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

3 trainers at level 40

Cinderace2.01
Toucannon2.01
Chandelure2.02
Darmanitan (Standard)2.05
Naganadel2.07
Heatran2.08

The party these numbers assume

1. Blacephalon

Incinerate + Mind Blown

2. Kyurem (White)

Ice Fang + Ice Burn

3. Rayquaza

Air Slash + Dragon Ascent

4. Eternatus

Poison Jab + Dynamax Cannon

5. Reshiram

Fire Fang + Fusion Flare

6. Kyurem (Black)

Dragon Tail + Freeze Shock

See the full ranked counter list for Gossifleur · 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.