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 1 to be safe — 1 if everyone is prepared

At level 40, a party of Cobalion's top six counters needs 0.10 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.13 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 0:19. A prepared solo becomes possible at level 20. A duo works from level 20.

Cobalion · Tier 1

steelfighting

Weak to

fightinggroundfire

Boss CP: 7,920
Boss HP: 600
Raid timer: 180s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Cobalion 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	1(0.14)	1(0.15)	1(0.18)	0:27	0.6
Level 25	1(0.13)	1(0.12)	1(0.16)	0:22	0.2
Level 30	1(0.10)	1(0.11)	1(0.14)	0:20	0.1
Level 35	1(0.10)	1(0.11)	1(0.13)	0:19	0.0
Level 40	1(0.09)	1(0.10)	1(0.13)	0:19	0.0
Level 45	1(0.09)	1(0.10)	1(0.13)	0:19	0.0
Level 50	1(0.09)	1(0.10)	1(0.12)	0:19	0.0

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.

1 trainer at level 40

Blacephalon0.09

A prepared party

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

1 trainer at level 40

Blacephalon0.09
Keldeo0.11
Terrakion0.11
Lucario0.11
Blaziken0.11
Landorus (Therian)0.11

A mixed local group

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

1 trainer at level 40

Reshiram0.12
Heatran0.12
Groudon0.13
Gallade0.13
Kartana0.13
Mamoswine0.13

The party these numbers assume

1. Blacephalon

Incinerate + Mind Blown

2. Keldeo

Low Kick + Secret Sword

3. Terrakion

Double Kick + Sacred Sword

4. Lucario

Force Palm + Aura Sphere

5. Blaziken

Counter + Aura Sphere

6. Landorus (Therian)

Mud Shot + Sandsear Storm

See the full ranked counter list for Cobalion · 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.