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 — 1 if everyone is prepared

At level 40, a party of Aron's top six counters needs 0.92 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 1.15 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 4:13. A prepared solo becomes possible at level 35. A duo works from level 20.

Aron · Tier 5

steelrock

Weak to

fightinggroundwater

Boss CP: 20,803
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 Aron 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(1.09)	2(1.26)	2(1.59)	5:49	5.9
Level 25	1(0.95)	2(1.11)	2(1.39)	5:06	5.5
Level 30	1(0.87)	2(1.00)	2(1.25)	4:36	4.8
Level 35	1(0.83)	1(0.96)	2(1.19)	4:25	4.4
Level 40	1(0.80)	1(0.92)	2(1.15)	4:13	4.0
Level 45	1(0.78)	1(0.89)	2(1.10)	4:05	3.6
Level 50	1(0.75)	1(0.86)	2(1.07)	3:57	3.3

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.

1 trainer at level 40

Keldeo0.80

A prepared party

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

1 trainer at level 40

Keldeo0.80
Lucario0.86
Terrakion0.92
Blaziken0.94
Landorus (Therian)0.96
Groudon1.02

A mixed local group

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

2 trainers at level 40

Breloom1.10
Kartana1.10
Marshadow1.12
Mewtwo1.13
Mamoswine1.14
Machamp1.15

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Lucario

Force Palm + Aura Sphere

3. Terrakion

Double Kick + Sacred Sword

4. Blaziken

Counter + Aura Sphere

5. Landorus (Therian)

Mud Shot + Sandsear Storm

6. Groudon

Mud Shot + Precipice Blades

See the full ranked counter list for Aron · 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.