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 Alolan Raichu's top six counters needs 0.57 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.67 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 1:40. A prepared solo becomes possible at level 20. A duo works from level 20.

Alolan Raichu · Tier 3

electricpsychic

Weak to

groundbugghostdark

Boss CP: 16,848
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 Alolan Raichu 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(0.67)	1(0.85)	2(1.00)	2:30	5.3
Level 25	1(0.61)	1(0.73)	1(0.85)	2:08	4.4
Level 30	1(0.54)	1(0.65)	1(0.74)	1:54	3.6
Level 35	1(0.54)	1(0.62)	1(0.70)	1:49	3.3
Level 40	1(0.48)	1(0.57)	1(0.67)	1:40	2.8
Level 45	1(0.47)	1(0.56)	1(0.65)	1:38	2.5
Level 50	1(0.47)	1(0.55)	1(0.63)	1:36	2.3

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

Necrozma (Dawn Wings)0.48

A prepared party

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

1 trainer at level 40

Necrozma (Dawn Wings)0.48
Landorus (Therian)0.55
Darkrai0.59
Blacephalon0.58
Groudon0.62
Chandelure0.62

A mixed local group

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

1 trainer at level 40

Gholdengo0.65
Gengar0.65
Absol0.66
Hoopa0.67
Excadrill0.67
Pheromosa0.65

The party these numbers assume

1. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

2. Landorus (Therian)

Mud Shot + Sandsear Storm

3. Darkrai

Snarl + Foul Play

4. Blacephalon

Astonish + Shadow Ball

5. Groudon

Mud Shot + Precipice Blades

6. Chandelure

Hex + Shadow Ball

See the full ranked counter list for Alolan Raichu · 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.