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 Natu's top six counters needs 1.53 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.93 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 7:03. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Natu · Elite

psychicflying

Weak to

rockghostelectricicedark

Boss CP: 21,489
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 Natu 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(2.05)	3(2.19)	3(2.75)	10:05	6.0
Level 25	2(1.76)	2(1.90)	3(2.37)	8:46	6.0
Level 30	2(1.57)	2(1.67)	3(2.11)	7:40	6.0
Level 35	2(1.54)	2(1.60)	3(2.02)	7:23	5.9
Level 40	2(1.44)	2(1.53)	2(1.93)	7:03	5.9
Level 45	2(1.40)	2(1.46)	2(1.85)	6:44	5.8
Level 50	2(1.39)	2(1.42)	2(1.79)	6:32	5.7

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

Kyurem (Black)1.44

A prepared party

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

2 trainers at level 40

Kyurem (Black)1.44
Kyurem (White)1.44
Necrozma (Dawn Wings)1.47
Regieleki1.54
Zeraora1.65
Thundurus (Therian)1.67

A mixed local group

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

2 trainers at level 40

Zamazenta (Crowned Shield)1.88
Lunala1.91
Absol1.91
Tyranitar1.91
Glimmora1.93
Eternatus1.92

The party these numbers assume

1. Kyurem (Black)

Shadow Claw + Freeze Shock

2. Kyurem (White)

Ice Fang + Ice Burn

3. Necrozma (Dawn Wings)

Shadow Claw + Moongeist Beam

4. Regieleki

Lock-On + Thunder Cage

5. Zeraora

Volt Switch + Plasma Fists

6. Thundurus (Therian)

Volt Switch + Wildbolt Storm

See the full ranked counter list for Natu · 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.