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 3 to be safe — 2 if everyone is prepared

At level 40, a party of Hatenna's top six counters needs 1.81 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.06 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:20. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Hatenna · Elite

psychic

Weak to

bugghostdark

Boss CP: 16,607
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 Hatenna 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(2.02)	3(2.55)	3(2.92)	11:44	6.0
Level 25	2(1.76)	3(2.24)	3(2.54)	10:18	5.8
Level 30	2(1.59)	2(1.99)	3(2.26)	9:09	5.5
Level 35	2(1.49)	2(1.88)	3(2.16)	8:40	5.3
Level 40	2(1.43)	2(1.81)	3(2.06)	8:20	5.2
Level 45	2(1.39)	2(1.76)	2(1.99)	8:06	5.1
Level 50	2(1.33)	2(1.68)	2(1.92)	7:44	4.9

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)1.43

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)1.43
Blacephalon1.77
Darkrai1.81
Lunala1.95
Kyurem (Black)1.95
Chandelure1.95

A mixed local group

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

3 trainers at level 40

Eternatus2.00
Dragapult2.01
Gengar2.03
Giratina (Origin)2.05
Hoopa2.05
Zamazenta (Crowned Shield)2.05

The party these numbers assume

1. Necrozma (Dawn Wings)

Shadow Claw + Moongeist Beam

2. Blacephalon

Astonish + Shadow Ball

3. Darkrai

Snarl + Foul Play

4. Lunala

Shadow Claw + Shadow Ball

5. Kyurem (Black)

Shadow Claw + Freeze Shock

6. Chandelure

Hex + Shadow Ball

See the full ranked counter list for Hatenna · 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.