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 Zamazenta's top six counters needs 0.81 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.97 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 2:22. A prepared solo becomes possible at level 30. A duo works from level 20.

Zamazenta · Tier 3

fighting

Weak to

flyingpsychicfairy

Boss CP: 25,570
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 Zamazenta 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(1.13)	2(1.20)	2(1.43)	3:31	5.9
Level 25	1(0.98)	2(1.03)	2(1.23)	3:01	5.6
Level 30	1(0.86)	1(0.92)	2(1.08)	2:41	5.1
Level 35	1(0.78)	1(0.85)	2(1.01)	2:29	4.5
Level 40	1(0.76)	1(0.81)	1(0.97)	2:22	4.3
Level 45	1(0.70)	1(0.78)	1(0.94)	2:17	3.9
Level 50	1(0.69)	1(0.75)	1(0.89)	2:11	3.6

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.

1 trainer at level 40

Rayquaza0.76

A prepared party

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

1 trainer at level 40

Rayquaza0.76
Mewtwo0.75
Enamorus (Incarnate)0.80
Hoopa (Unbound)0.83
Zacian (Crowned Sword)0.85
Galarian Articuno0.86

A mixed local group

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

1 trainer at level 40

Necrozma (Dawn Wings)0.93
Lunala0.94
Lugia0.95
Salamence0.94
Eternatus0.96
Tornadus (Therian)0.96

The party these numbers assume

1. Rayquaza

Air Slash + Dragon Ascent

2. Mewtwo

Psycho Cut + Psystrike

3. Enamorus (Incarnate)

Fairy Wind + Fly

4. Hoopa (Unbound)

Confusion + Psychic

5. Zacian (Crowned Sword)

Air Slash + Play Rough

6. Galarian Articuno

Psycho Cut + Fly

See the full ranked counter list for Zamazenta · 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.