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 — 3 if everyone is prepared

At level 40, a party of Mewtwo's top six counters needs 2.12 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 2.43 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 9:45. No level in this range makes it soloable with a prepared party. A duo works from level 50.

Mewtwo · Tier 5

psychic

Weak to

bugghostdark

Boss CP: 54,148
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 Mewtwo 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(2.52)	4(3.29)	4(3.78)	15:09	6.0
Level 25	3(2.11)	3(2.72)	4(3.16)	12:30	6.0
Level 30	2(1.81)	3(2.40)	3(2.70)	11:04	5.9
Level 35	2(1.72)	3(2.24)	3(2.52)	10:20	5.9
Level 40	2(1.67)	3(2.12)	3(2.43)	9:45	5.9
Level 45	2(1.59)	3(2.03)	3(2.34)	9:19	5.9
Level 50	2(1.55)	2(1.95)	3(2.25)	8:58	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

Necrozma (Dawn Wings)1.67

A prepared party

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

3 trainers at level 40

Necrozma (Dawn Wings)1.67
Lunala2.16
Blacephalon2.18
Darkrai2.17
Giratina (Origin)2.26
Eternatus2.27

A mixed local group

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

3 trainers at level 40

Zacian (Crowned Sword)2.33
Hoopa (Unbound)2.37
Zamazenta (Crowned Shield)2.37
Hoopa2.40
Tyranitar2.32
Volcarona2.44

The party these numbers assume

1. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

2. Lunala

Shadow Claw + Shadow Ball

3. Blacephalon

Astonish + Shadow Ball

4. Darkrai

Snarl + Foul Play

5. Giratina (Origin)

Shadow Claw + Shadow Force

6. Eternatus

Poison Jab + Dynamax Cannon

See the full ranked counter list for Mewtwo · 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.