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 4 to be safe — 3 if everyone is prepared

At level 40, a party of Iron Valiant's top six counters needs 2.47 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.26 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 11:22. No level in this range makes it soloable with a prepared party.

Iron Valiant · Elite

fairyfighting

Weak to

flyingpoisonsteelpsychicfairy

Boss CP: 56,704
Boss HP: 20,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Iron Valiant 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(2.99)	4(3.44)	5(4.48)	15:50	5.8
Level 25	3(2.55)	3(2.99)	4(3.94)	13:46	5.4
Level 30	3(2.33)	3(2.68)	4(3.55)	12:21	5.0
Level 35	3(2.26)	3(2.56)	4(3.41)	11:46	4.9
Level 40	3(2.17)	3(2.47)	4(3.26)	11:22	4.8
Level 45	3(2.10)	3(2.39)	4(3.14)	10:59	4.5
Level 50	2(2.00)	3(2.29)	4(3.05)	10:32	4.4

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

Necrozma (Dusk Mane)2.17

A prepared party

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

3 trainers at level 40

Necrozma (Dusk Mane)2.17
Zacian (Crowned Sword)2.19
Zamazenta (Crowned Shield)2.26
Mewtwo2.68
Rayquaza2.72
Enamorus (Incarnate)2.80

A mixed local group

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

4 trainers at level 40

Tinkaton3.07
Moltres3.10
Yveltal3.13
Enamorus (Therian)3.20
Toucannon3.23
Lunala3.29

The party these numbers assume

1. Necrozma (Dusk Mane)

Psycho Cut + Sunsteel Strike

2. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

3. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

4. Mewtwo

Psycho Cut + Psystrike

5. Rayquaza

Air Slash + Dragon Ascent

6. Enamorus (Incarnate)

Fairy Wind + Fly

See the full ranked counter list for Iron Valiant · 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.