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 4 to be safe — 4 if everyone is prepared

At level 40, a party of Tornadus (Incarnate)'s top six counters needs 3.17 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 3.94 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 14:59. No level in this range makes it soloable with a prepared party.

Tornadus (Incarnate) · Shadow Tier 5

flying

Weak to

rockelectricice

Boss CP: 46,044
Boss HP: 15,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Tornadus (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	5(4.57)	6(5.50)	7(6.48)	25:58	6.0
Level 25	4(3.54)	5(4.29)	6(5.30)	20:15	6.0
Level 30	4(3.00)	4(3.62)	5(4.59)	17:06	6.0
Level 35	3(2.82)	4(3.32)	5(4.26)	15:40	6.0
Level 40	3(2.76)	4(3.17)	4(3.94)	14:59	6.0
Level 45	3(2.69)	4(3.04)	4(3.79)	14:22	6.0
Level 50	3(2.57)	3(2.91)	4(3.64)	13:45	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.

3 trainers at level 40

Kyurem (White)2.76

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)2.76
Kyurem (Black)3.04
Zeraora3.17
Regieleki3.22
Zekrom3.37
Thundurus (Therian)3.47

A mixed local group

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

4 trainers at level 40

Necrozma (Dusk Mane)3.75
Zacian (Crowned Sword)3.74
Baxcalibur3.82
Tyrantrum3.87
Necrozma (Dawn Wings)3.92
Electivire3.91

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Zeraora

Spark + Plasma Fists

4. Regieleki

Thunder Shock + Thunder Cage

5. Zekrom

Charge Beam + Fusion Bolt

6. Thundurus (Therian)

Volt Switch + Wildbolt Storm

See the full ranked counter list for Tornadus (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.