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 4 to be safe — 3 if everyone is prepared

At level 40, a party of Zygarde (Ten Percent)'s top six counters needs 2.23 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.02 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 10:17. No level in this range makes it soloable with a prepared party.

Zygarde (Ten Percent) · Elite

dragonground

Weak to

icedragonfairy

Boss CP: 42,659
Boss HP: 20,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Zygarde (Ten Percent) 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	4(3.05)	5(4.07)	6(5.04)	18:43	6.0
Level 25	3(2.49)	4(3.27)	5(4.20)	15:04	6.0
Level 30	2(1.87)	3(2.51)	4(3.50)	11:33	6.0
Level 35	2(1.79)	3(2.36)	4(3.25)	10:51	6.0
Level 40	2(1.72)	3(2.23)	4(3.02)	10:17	6.0
Level 45	2(1.66)	3(2.13)	3(2.91)	9:49	6.0
Level 50	2(1.60)	3(2.05)	3(2.81)	9:26	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

Kyurem (White)1.72

A prepared party

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

3 trainers at level 40

Kyurem (White)1.72
Kyurem (Black)1.95
Eternatus2.35
Baxcalibur2.44
Galarian Darmanitan (Standard)2.49
Mamoswine2.45

A mixed local group

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

4 trainers at level 40

Palkia (Origin)2.93
Rayquaza2.92
Mr. Rime2.94
Aurorus2.99
Dialga (Origin)3.00
Avalugg3.03

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Eternatus

Dragon Tail + Dynamax Cannon

4. Baxcalibur

Ice Fang + Avalanche

5. Galarian Darmanitan (Standard)

Ice Fang + Avalanche

6. Mamoswine

Powder Snow + Avalanche

See the full ranked counter list for Zygarde (Ten Percent) · 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.