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 Mega Froslass's top six counters needs 2.74 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.65 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 12:43. No level in this range makes it soloable with a prepared party.

Mega Froslass · Primal

iceghost

Weak to

rockghoststeelfiredark

Boss CP: 65,923
Boss HP: 22,500
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Mega Froslass 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	4(3.21)	5(4.02)	6(5.70)	18:42	6.0
Level 25	3(2.80)	4(3.58)	5(4.70)	16:39	6.0
Level 30	3(2.48)	4(3.07)	5(4.02)	14:15	6.0
Level 35	3(2.32)	3(2.90)	4(3.79)	13:28	6.0
Level 40	3(2.26)	3(2.74)	4(3.65)	12:43	6.0
Level 45	3(2.22)	3(2.65)	4(3.49)	12:20	6.0
Level 50	3(2.15)	3(2.54)	4(3.37)	11:49	5.9

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.

3 trainers at level 40

Zamazenta (Crowned Shield)2.26

A prepared party

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

3 trainers at level 40

Zamazenta (Crowned Shield)2.26
Zacian (Crowned Sword)2.30
Necrozma (Dusk Mane)2.35
Reshiram3.08
Kyurem (White)3.16
Darkrai3.28

A mixed local group

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

4 trainers at level 40

Rampardos3.60
Darmanitan (Standard)3.62
Eternatus3.63
Volcarona3.62
Lucario3.64
Dialga (Origin)3.64

The party these numbers assume

1. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

2. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

3. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

4. Reshiram

Fire Fang + Fusion Flare

5. Kyurem (White)

Steel Wing + Fusion Flare

6. Darkrai

Snarl + Foul Play

See the full ranked counter list for Mega Froslass · 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.