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 2 to be safe — 2 if everyone is prepared

At level 40, a party of Grumpig's top six counters needs 1.45 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.64 (round up: 2). The raid timer is 180 seconds and one prepared trainer alone would take 4:14. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Grumpig · Shadow Tier 3

psychic

Weak to

bugghostdark

Boss CP: 16,760
Boss HP: 4,000
Raid timer: 180s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Grumpig 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(2.01)	3(2.18)	3(2.45)	6:23	5.4
Level 25	2(1.61)	2(1.88)	3(2.10)	5:29	5.0
Level 30	2(1.25)	2(1.65)	2(1.85)	4:49	4.6
Level 35	2(1.18)	2(1.57)	2(1.77)	4:35	4.4
Level 40	2(1.17)	2(1.45)	2(1.64)	4:14	4.3
Level 45	2(1.11)	2(1.40)	2(1.60)	4:06	4.1
Level 50	2(1.09)	2(1.37)	2(1.55)	4:01	3.9

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

Necrozma (Dawn Wings)1.17

A prepared party

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

2 trainers at level 40

Necrozma (Dawn Wings)1.17
Darkrai1.41
Blacephalon1.49
Hydreigon1.52
Necrozma (Dusk Mane)1.53
Eternatus1.55

A mixed local group

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

2 trainers at level 40

Gholdengo1.60
Zacian (Crowned Sword)1.61
Dragapult1.63
Hisuian Zoroark1.63
Hoopa (Unbound)1.63
Incineroar1.63

The party these numbers assume

1. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

2. Darkrai

Snarl + Foul Play

3. Blacephalon

Astonish + Shadow Ball

4. Hydreigon

Bite + Brutal Swing

5. Necrozma (Dusk Mane)

Shadow Claw + Sunsteel Strike

6. Eternatus

Dragon Tail + Dynamax Cannon

See the full ranked counter list for Grumpig · 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.