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 Thundurus (Incarnate)'s top six counters needs 3.15 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.01 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 14:29. No level in this range makes it soloable with a prepared party.

Thundurus (Incarnate) · Elite

electricflying

Weak to

rockice

Boss CP: 53,167
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 Thundurus (Incarnate) 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	4(3.65)	5(4.82)	7(6.17)	22:11	6.0
Level 25	4(3.09)	4(3.96)	6(5.17)	18:14	6.0
Level 30	3(2.78)	4(3.48)	5(4.44)	16:00	6.0
Level 35	3(2.62)	4(3.32)	5(4.20)	15:15	5.9
Level 40	3(2.51)	4(3.15)	5(4.01)	14:29	5.9
Level 45	3(2.39)	4(3.05)	4(3.87)	14:02	5.9
Level 50	3(2.33)	3(2.93)	4(3.73)	13:29	5.8

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.

3 trainers at level 40

Kyurem (White)2.51

A prepared party

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

4 trainers at level 40

Kyurem (White)2.51
Kyurem (Black)2.73
Eternatus3.22
Glimmora3.43
Rhyperior3.46
Gigalith3.55

A mixed local group

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

5 trainers at level 40

Mamoswine3.69
Kyurem3.72
Regigigas3.83
Weavile3.88
Cetitan4.03
Glaceon4.02

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Eternatus

Poison Jab + Dynamax Cannon

4. Glimmora

Rock Throw + Meteor Beam

5. Rhyperior

Smack Down + Rock Wrecker

6. Gigalith

Lock-On + Meteor Beam

See the full ranked counter list for Thundurus (Incarnate) · 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.