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 1 to be safe — 1 if everyone is prepared

At level 40, a party of Zygarde (Ten Percent)'s top six counters needs 0.44 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.61 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 1:17. A prepared solo becomes possible at level 20. A duo works from level 20.

Zygarde (Ten Percent) · Tier 3

dragonground

Weak to

icedragonfairy

Boss CP: 18,098
Boss HP: 3,600
Raid timer: 180s
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	1(0.51)	1(0.69)	1(0.92)	2:02	5.3
Level 25	1(0.42)	1(0.55)	1(0.77)	1:36	4.2
Level 30	1(0.38)	1(0.48)	1(0.67)	1:25	3.4
Level 35	1(0.36)	1(0.46)	1(0.63)	1:20	3.1
Level 40	1(0.35)	1(0.44)	1(0.61)	1:17	2.9
Level 45	1(0.34)	1(0.43)	1(0.59)	1:15	2.6
Level 50	1(0.33)	1(0.41)	1(0.57)	1:12	2.2

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.

1 trainer at level 40

Kyurem (White)0.35

A prepared party

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

1 trainer at level 40

Kyurem (White)0.35
Kyurem (Black)0.37
Eternatus0.46
Galarian Darmanitan (Standard)0.47
Baxcalibur0.49
Mamoswine0.50

A mixed local group

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

1 trainer at level 40

Mr. Rime0.57
Aurorus0.59
Mewtwo0.59
Palkia (Origin)0.61
Rayquaza0.61
Avalugg0.60

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. Galarian Darmanitan (Standard)

Ice Fang + Avalanche

5. Baxcalibur

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.