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 Psyduck's top six counters needs 0.35 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.45 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 1:02. A prepared solo becomes possible at level 20. A duo works from level 20.

Psyduck · Tier 3

water

Weak to

grasselectric

Boss CP: 8,621
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 Psyduck 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(0.46)	1(0.49)	1(0.61)	1:26	2.3
Level 25	1(0.40)	1(0.43)	1(0.54)	1:16	1.5
Level 30	1(0.36)	1(0.39)	1(0.48)	1:09	1.0
Level 35	1(0.35)	1(0.37)	1(0.46)	1:06	0.8
Level 40	1(0.33)	1(0.35)	1(0.45)	1:02	0.7
Level 45	1(0.31)	1(0.35)	1(0.43)	1:01	0.6
Level 50	1(0.30)	1(0.34)	1(0.41)	1:00	0.5

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

Regieleki0.33

A prepared party

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

1 trainer at level 40

Regieleki0.33
Kartana0.36
Thundurus (Therian)0.35
Zekrom0.36
Zeraora0.35
Xurkitree0.36

A mixed local group

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

1 trainer at level 40

Roserade0.43
Raikou0.43
Deoxys0.44
Zapdos0.44
Kyurem (Black)0.44
Breloom0.44

The party these numbers assume

1. Regieleki

Thunder Shock + Thunder Cage

2. Kartana

Razor Leaf + Leaf Blade

3. Thundurus (Therian)

Volt Switch + Wildbolt Storm

4. Zekrom

Charge Beam + Fusion Bolt

5. Zeraora

Volt Switch + Plasma Fists

6. Xurkitree

Thunder Shock + Power Whip

See the full ranked counter list for Psyduck · 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.