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 2 to be safe — 2 if everyone is prepared

At level 40, a party of Darkrai's top six counters needs 1.48 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.84 (round up: 2). The raid timer is 180 seconds and one prepared trainer alone would take 4:20. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Darkrai · Shadow Tier 3

dark

Weak to

fightingbugfairy

Boss CP: 27,691
Boss HP: 4,000
Raid timer: 180s
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	2(1.90)	3(2.26)	3(2.86)	6:36	6.0
Level 25	2(1.51)	2(1.92)	3(2.41)	5:38	6.0
Level 30	2(1.34)	2(1.63)	3(2.08)	4:45	6.0
Level 35	2(1.28)	2(1.55)	2(1.96)	4:32	5.9
Level 40	2(1.25)	2(1.48)	2(1.84)	4:20	5.9
Level 45	2(1.21)	2(1.43)	2(1.78)	4:11	5.8
Level 50	2(1.18)	2(1.38)	2(1.72)	4:03	5.7

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.

2 trainers at level 40

Keldeo1.25

A prepared party

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

2 trainers at level 40

Keldeo1.25
Kartana1.47
Lucario1.50
Terrakion1.53
Zacian (Crowned Sword)1.51
Blaziken1.61

A mixed local group

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

2 trainers at level 40

Urshifu (Single Strike)1.73
Tapu Koko1.79
Tapu Bulu1.80
Raikou1.82
Togekiss1.82
Galarian Zapdos1.85

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Kartana

Fury Cutter + Sacred Sword

3. Lucario

Force Palm + Aura Sphere

4. Terrakion

Double Kick + Sacred Sword

5. Zacian (Crowned Sword)

Metal Claw + Play Rough

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.