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 5 to be safe — 4 if everyone is prepared

At level 40, a party of Darkrai's top six counters needs 3.85 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.66 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 18:12. No level in this range makes it soloable with a prepared party.

Darkrai · Shadow Tier 5

dark

Weak to

fightingbugfairy

Boss CP: 53,623
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 Darkrai 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	5(4.82)	6(5.87)	8(7.91)	27:44	6.0
Level 25	5(4.32)	6(5.19)	7(6.15)	24:30	6.0
Level 30	4(3.45)	5(4.37)	6(5.21)	20:37	6.0
Level 35	4(3.27)	5(4.06)	5(4.95)	19:11	6.0
Level 40	4(3.16)	4(3.85)	5(4.66)	18:12	6.0
Level 45	4(3.00)	4(3.69)	5(4.54)	17:26	6.0
Level 50	3(2.88)	4(3.54)	5(4.42)	16:43	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.

4 trainers at level 40

Keldeo3.16

A prepared party

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

4 trainers at level 40

Keldeo3.16
Zacian (Crowned Sword)3.76
Lucario3.92
Terrakion4.02
Kartana4.12
Blaziken4.13

A mixed local group

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

5 trainers at level 40

Tapu Koko4.46
Marshadow4.59
Machamp4.61
Hisuian Decidueye4.66
Vikavolt4.67
Raikou4.67

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Zacian (Crowned Sword)

Metal Claw + Play Rough

3. Lucario

Force Palm + Aura Sphere

4. Terrakion

Double Kick + Sacred Sword

5. Kartana

Fury Cutter + Sacred Sword

6. Blaziken

Counter + Aura Sphere

See the full ranked counter list for Darkrai · 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.