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 1 to be safe — 1 if everyone is prepared

At level 40, a party of Gourgeist (Super)'s top six counters needs 0.65 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.80 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 1:55. A prepared solo becomes possible at level 20. A duo works from level 20.

Gourgeist (Super) · Tier 3

ghostgrass

Weak to

flyingghostfireicedark

Boss CP: 17,331
Boss HP: 3,600
Raid timer: 180s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Gourgeist (Super) 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	1(0.84)	1(0.98)	2(1.15)	2:52	5.2
Level 25	1(0.76)	1(0.86)	1(1.00)	2:30	4.5
Level 30	1(0.67)	1(0.73)	1(0.88)	2:08	3.8
Level 35	1(0.64)	1(0.69)	1(0.84)	2:01	3.3
Level 40	1(0.62)	1(0.65)	1(0.80)	1:55	3.0
Level 45	1(0.60)	1(0.63)	1(0.77)	1:50	2.8
Level 50	1(0.58)	1(0.60)	1(0.75)	1:46	2.5

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

Kyurem (White)0.62

A prepared party

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

1 trainer at level 40

Kyurem (White)0.62
Rayquaza0.64
Necrozma (Dawn Wings)0.63
Kyurem (Black)0.64
Reshiram0.70
Blacephalon0.70

A mixed local group

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

1 trainer at level 40

Honchkrow0.78
Heatran0.79
Blaziken0.79
Staraptor0.79
Galarian Articuno0.79
Cinderace0.81

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Rayquaza

Air Slash + Dragon Ascent

3. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

4. Kyurem (Black)

Shadow Claw + Freeze Shock

5. Reshiram

Fire Fang + Fusion Flare

6. Blacephalon

Astonish + Mind Blown

See the full ranked counter list for Gourgeist (Super) · 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.