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 Primal Groudon's top six counters needs 3.67 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.57 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 17:02. No level in this range makes it soloable with a prepared party.

Primal Groudon · Mega Legendary

groundfire

Weak to

waterground

Boss CP: 92,860
Boss HP: 22,500
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Primal Groudon 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	6(5.31)	7(6.01)	8(7.25)	27:56	6.0
Level 25	5(4.75)	6(5.12)	7(6.31)	23:48	6.0
Level 30	4(3.83)	5(4.46)	6(5.47)	20:45	6.0
Level 35	4(3.57)	4(3.95)	6(5.07)	18:21	6.0
Level 40	4(3.36)	4(3.67)	5(4.57)	17:02	6.0
Level 45	4(3.32)	4(3.57)	5(4.37)	16:36	6.0
Level 50	4(3.18)	4(3.44)	5(4.13)	15:59	6.0

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

Kyogre3.36

A prepared party

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

4 trainers at level 40

Kyogre3.36
Golisopod3.56
Primarina3.66
Gyarados3.80
Inteleon3.81
Swampert3.81

A mixed local group

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

5 trainers at level 40

Quaquaval4.22
Volcanion4.55
Mew4.59
Empoleon4.56
Clawitzer4.51
Hisuian Samurott4.58

The party these numbers assume

1. Kyogre

Waterfall + Surf

2. Golisopod

Waterfall + Razor Shell

3. Primarina

Waterfall + Hydro Cannon

4. Gyarados

Waterfall + Aqua Tail

5. Inteleon

Water Gun + Hydro Cannon

6. Swampert

Water Gun + Hydro Cannon

See the full ranked counter list for Primal Groudon · 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.