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 Bronzor's top six counters needs 1.52 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.82 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 6:59. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Bronzor · Tier 5

steelpsychic

Weak to

groundghostfiredark

Boss CP: 9,234
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 Bronzor 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	2(1.84)	3(2.05)	3(2.51)	9:27	4.8
Level 25	2(1.58)	2(1.82)	3(2.20)	8:23	4.1
Level 30	2(1.45)	2(1.64)	2(1.98)	7:34	3.5
Level 35	2(1.39)	2(1.58)	2(1.91)	7:16	3.2
Level 40	2(1.32)	2(1.52)	2(1.82)	6:59	2.9
Level 45	2(1.28)	2(1.46)	2(1.77)	6:42	2.8
Level 50	2(1.24)	2(1.42)	2(1.72)	6:32	2.7

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

Blacephalon1.32

A prepared party

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

2 trainers at level 40

Blacephalon1.32
Necrozma (Dawn Wings)1.36
Reshiram1.53
Landorus (Therian)1.59
Darkrai1.65
Chandelure1.66

A mixed local group

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

2 trainers at level 40

Lunala1.79
Absol1.79
Hydreigon1.80
Gengar1.81
Delphox1.81
Hisuian Zoroark1.81

The party these numbers assume

1. Blacephalon

Astonish + Mind Blown

2. Necrozma (Dawn Wings)

Shadow Claw + Moongeist Beam

3. Reshiram

Fire Fang + Fusion Flare

4. Landorus (Therian)

Mud Shot + Sandsear Storm

5. Darkrai

Snarl + Foul Play

6. Chandelure

Fire Spin + Shadow Ball

See the full ranked counter list for Bronzor · 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.