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 — 3 if everyone is prepared

At level 40, a party of Iron Bundle's top six counters needs 2.02 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 2.41 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 9:18. No level in this range makes it soloable with a prepared party. A duo works from level 45.

Iron Bundle · Tier 5

icewater

Weak to

fightingrockgrasselectric

Boss CP: 51,737
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 Iron Bundle 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(2.50)	3(2.82)	4(3.37)	13:00	6.0
Level 25	3(2.29)	3(2.48)	3(2.95)	11:25	6.0
Level 30	2(2.00)	3(2.21)	3(2.65)	10:11	5.7
Level 35	2(1.92)	3(2.10)	3(2.54)	9:40	5.5
Level 40	2(1.87)	3(2.02)	3(2.41)	9:18	5.4
Level 45	2(1.75)	2(1.94)	3(2.33)	8:56	5.2
Level 50	2(1.72)	2(1.88)	3(2.28)	8:40	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

Keldeo1.87

A prepared party

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

3 trainers at level 40

Keldeo1.87
Regieleki1.93
Lucario2.01
Kartana2.10
Thundurus (Therian)2.09
Zeraora2.12

A mixed local group

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

3 trainers at level 40

Necrozma (Dawn Wings)2.38
Glimmora2.38
Eternatus2.39
Raikou2.40
Hisuian Decidueye2.40
Pheromosa2.38

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Regieleki

Lock-On + Thunder Cage

3. Lucario

Force Palm + Aura Sphere

4. Kartana

Razor Leaf + Leaf Blade

5. Thundurus (Therian)

Volt Switch + Wildbolt Storm

6. Zeraora

Volt Switch + Plasma Fists

See the full ranked counter list for Iron Bundle · 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.