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 7 to be safe — 5 if everyone is prepared

At level 40, a party of Regice's top six counters needs 4.76 trainers (round up: 5), and a mixed lobby of ranks 13-24 needs 6.52 (round up: 7). The raid timer is 300 seconds and one prepared trainer alone would take 22:30. No level in this range makes it soloable with a prepared party.

Regice · Shadow 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	8(7.22)	8(7.78)	11(10.01)	36:45	6.0
Level 25	6(5.71)	7(6.12)	9(8.54)	28:54	6.0
Level 30	5(4.53)	6(5.26)	8(7.60)	24:49	6.0
Level 35	5(4.37)	6(5.07)	7(6.97)	23:55	6.0
Level 40	5(4.19)	5(4.76)	7(6.52)	22:30	6.0
Level 45	5(4.13)	5(4.64)	7(6.24)	21:54	6.0
Level 50	5(4.03)	5(4.48)	6(5.91)	21:10	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.

5 trainers at level 40

Zacian (Crowned Sword)4.19

A prepared party

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

5 trainers at level 40

Zacian (Crowned Sword)4.19
Zamazenta (Crowned Shield)4.23
Necrozma (Dusk Mane)4.42
Keldeo4.52
Blacephalon5.65
Reshiram5.57

A mixed local group

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

7 trainers at level 40

Ho-Oh6.35
Urshifu (Rapid Strike)6.39
Delphox6.44
Raikou6.49
Eternatus6.56
Volcarona6.55

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)

Psycho Cut + Sunsteel Strike

4. Keldeo

Low Kick + Secret Sword

5. Blacephalon

Incinerate + Mind Blown

6. Reshiram

Fire Fang + Fusion Flare

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.