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 3 to be safe — 2 if everyone is prepared

At level 40, a party of Mega Darkrai's top six counters needs 1.67 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.05 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 7:46. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Mega Darkrai · Mega

dark

Weak to

fightingbugfairy

Boss CP: 53,973
Boss HP: 9,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Mega 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	3(2.10)	3(2.54)	4(3.32)	11:47	6.0
Level 25	2(1.81)	3(2.22)	3(2.76)	10:18	6.0
Level 30	2(1.54)	2(1.87)	3(2.35)	8:42	6.0
Level 35	2(1.48)	2(1.76)	3(2.18)	8:10	6.0
Level 40	2(1.38)	2(1.67)	3(2.05)	7:46	6.0
Level 45	2(1.32)	2(1.63)	2(1.98)	7:35	6.0
Level 50	2(1.23)	2(1.53)	2(1.91)	7:06	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.

2 trainers at level 40

Keldeo1.38

A prepared party

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

2 trainers at level 40

Keldeo1.38
Zacian (Crowned Sword)1.71
Lucario1.67
Terrakion1.69
Kartana1.75
Eternatus1.82

A mixed local group

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

3 trainers at level 40

Tapu Koko1.97
Raikou1.97
Togekiss2.01
Machamp2.04
Urshifu (Single Strike)1.99
Marshadow2.07

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. Eternatus

Poison Jab + Dynamax Cannon

See the full ranked counter list for Mega 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.