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 5 to be safe — 3 if everyone is prepared

At level 40, a party of Heatran's top six counters needs 2.98 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 4.01 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 14:05. No level in this range makes it soloable with a prepared party.

Heatran · Shadow Tier 5

firesteel

Weak to

groundfightingwater

Boss CP: 49,192
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 Heatran 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	5(4.30)	5(4.60)	7(6.40)	21:45	6.0
Level 25	4(3.80)	4(3.93)	6(5.50)	18:33	6.0
Level 30	4(3.13)	4(3.50)	5(4.65)	16:32	6.0
Level 35	3(2.74)	4(3.17)	5(4.24)	14:59	6.0
Level 40	3(2.62)	3(2.98)	5(4.01)	14:05	6.0
Level 45	3(2.58)	3(2.88)	4(3.86)	13:37	6.0
Level 50	3(2.45)	3(2.79)	4(3.72)	13:12	6.0

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.

3 trainers at level 40

Landorus (Therian)2.62

A prepared party

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

3 trainers at level 40

Landorus (Therian)2.62
Groudon2.72
Garchomp2.93
Landorus (Incarnate)3.16
Keldeo3.20
Rhyperior3.27

A mixed local group

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

5 trainers at level 40

Mudsdale3.76
Donphan3.82
Volcanion3.87
Swampert3.89
Terrakion3.98
Golurk4.02

The party these numbers assume

1. Landorus (Therian)

Mud Shot + Sandsear Storm

2. Groudon

Mud Shot + Precipice Blades

3. Garchomp

Mud Shot + Earth Power

4. Landorus (Incarnate)

Mud Shot + Earth Power

5. Keldeo

Low Kick + Secret Sword

6. Rhyperior

Mud-Slap + Earthquake

See the full ranked counter list for Heatran · 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.