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 Mega Golurk's top six counters needs 1.26 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.52 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 5:50. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Mega Golurk · Mega

groundghost

Weak to

ghostwatergrassicedark

Boss CP: 41,785
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 Golurk 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(1.71)	2(1.91)	3(2.44)	8:52	6.0
Level 25	2(1.39)	2(1.57)	2(2.00)	7:18	6.0
Level 30	2(1.26)	2(1.40)	2(1.70)	6:30	6.0
Level 35	2(1.19)	2(1.33)	2(1.60)	6:10	6.0
Level 40	2(1.13)	2(1.26)	2(1.52)	5:50	5.9
Level 45	2(1.06)	2(1.21)	2(1.47)	5:37	5.9
Level 50	2(1.02)	2(1.16)	2(1.41)	5:24	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.

2 trainers at level 40

Kyurem (White)1.13

A prepared party

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

2 trainers at level 40

Kyurem (White)1.13
Kyurem (Black)1.13
Necrozma (Dawn Wings)1.14
Shaymin (Sky)1.34
Darkrai1.37
Hydreigon1.42

A mixed local group

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

2 trainers at level 40

Eternatus1.47
Zamazenta (Crowned Shield)1.48
Lunala1.49
Primarina1.50
Giratina (Origin)1.50
Quaquaval1.52

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Shadow Claw + Freeze Shock

3. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

4. Shaymin (Sky)

Magical Leaf + Grass Knot

5. Darkrai

Snarl + Foul Play

6. Hydreigon

Bite + Brutal Swing

See the full ranked counter list for Mega Golurk · 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.