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 Chimecho's top six counters needs 1.49 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.71 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 6:54. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Mega Chimecho · Mega

psychic

Weak to

bugghostdark

Boss CP: 38,302
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 Chimecho 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(2.31)	3(2.30)	3(2.49)	10:42	6.0
Level 25	3(2.10)	2(1.98)	3(2.11)	9:13	6.0
Level 30	2(1.49)	2(1.69)	2(1.88)	7:52	5.9
Level 35	2(1.30)	2(1.55)	2(1.78)	7:12	5.8
Level 40	2(1.21)	2(1.49)	2(1.71)	6:54	5.7
Level 45	2(1.13)	2(1.44)	2(1.66)	6:42	5.6
Level 50	2(1.07)	2(1.40)	2(1.60)	6:31	5.6

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

Necrozma (Dawn Wings)1.21

A prepared party

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

2 trainers at level 40

Necrozma (Dawn Wings)1.21
Darkrai1.46
Hydreigon1.55
Kyurem (Black)1.56
Tyranitar1.55
Lunala1.60

A mixed local group

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

2 trainers at level 40

Gholdengo1.68
Weavile1.67
Giratina (Origin)1.67
Kingambit1.70
Volcarona1.70
Zamazenta (Crowned Shield)1.73

The party these numbers assume

1. Necrozma (Dawn Wings)

Shadow Claw + Moongeist Beam

2. Darkrai

Snarl + Foul Play

3. Hydreigon

Bite + Brutal Swing

4. Kyurem (Black)

Shadow Claw + Freeze Shock

5. Tyranitar

Bite + Brutal Swing

6. Lunala

Shadow Claw + Shadow Ball

See the full ranked counter list for Mega Chimecho · 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.