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 Regice's top six counters needs 2.69 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.58 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 12:22. No level in this range makes it soloable with a prepared party.

Regice · Tier 5

ice

Weak to

fightingrocksteelfire

Boss CP: 42,768
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 Regice 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(3.81)	5(4.16)	6(5.55)	19:10	6.0
Level 25	3(2.95)	4(3.39)	5(4.71)	15:36	6.0
Level 30	3(2.72)	4(3.02)	5(4.08)	13:54	6.0
Level 35	3(2.62)	3(2.87)	4(3.81)	13:12	6.0
Level 40	3(2.38)	3(2.69)	4(3.58)	12:22	6.0
Level 45	3(2.35)	3(2.64)	4(3.46)	12:08	6.0
Level 50	3(2.27)	3(2.55)	4(3.34)	11:45	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

Zacian (Crowned Sword)2.38

A prepared party

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

3 trainers at level 40

Zacian (Crowned Sword)2.38
Zamazenta (Crowned Shield)2.37
Necrozma (Dusk Mane)2.46
Keldeo2.60
Reshiram3.15
Terrakion3.17

A mixed local group

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

4 trainers at level 40

Kartana3.41
Chandelure3.51
Urshifu (Rapid Strike)3.50
Volcarona3.53
Urshifu (Single Strike)3.53
Heatran3.57

The party these numbers assume

1. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

2. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

3. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

4. Keldeo

Low Kick + Secret Sword

5. Reshiram

Fire Fang + Fusion Flare

6. Terrakion

Double Kick + Sacred Sword

See the full ranked counter list for Regice · 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.