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 — 2 if everyone is prepared

At level 40, a party of Zygarde (Fifty Percent)'s top six counters needs 1.72 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.35 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 7:55. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Zygarde (Fifty Percent) · Tier 5

dragonground

Weak to

icedragonfairy

Boss CP: 41,961
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 Zygarde (Fifty 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	2(1.99)	3(2.78)	4(3.66)	12:46	6.0
Level 25	2(1.66)	3(2.19)	4(3.04)	10:04	6.0
Level 30	2(1.49)	2(1.90)	3(2.59)	8:44	6.0
Level 35	2(1.39)	2(1.79)	3(2.46)	8:14	6.0
Level 40	2(1.34)	2(1.72)	3(2.35)	7:55	6.0
Level 45	2(1.28)	2(1.64)	3(2.28)	7:33	6.0
Level 50	2(1.24)	2(1.58)	3(2.18)	7:17	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)1.34

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)1.34
Kyurem (Black)1.50
Galarian Darmanitan (Standard)1.83
Eternatus1.84
Baxcalibur1.88
Mamoswine1.95

A mixed local group

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

3 trainers at level 40

Jynx2.28
Palkia (Origin)2.30
Aurorus2.29
Mr. Rime2.28
Rayquaza2.32
Avalugg2.34

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Galarian Darmanitan (Standard)

Ice Fang + Avalanche

4. Eternatus

Dragon Tail + Dynamax Cannon

5. Baxcalibur

Ice Fang + Avalanche

6. Mamoswine

Powder Snow + Avalanche

See the full ranked counter list for Zygarde (Fifty 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.