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 5 to be safe — 4 if everyone is prepared

At level 40, a party of Silvally (Poison)'s top six counters needs 3.46 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.20 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 15:56. No level in this range makes it soloable with a prepared party.

Silvally (Poison) · Elite

poison

Weak to

groundpsychic

Boss CP: 43,962
Boss HP: 20,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Silvally (Poison) 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	5(4.54)	5(4.95)	6(6.00)	22:47	6.0
Level 25	4(3.92)	5(4.32)	6(5.21)	19:54	6.0
Level 30	4(3.40)	4(3.88)	5(4.63)	17:50	5.9
Level 35	4(3.26)	4(3.65)	5(4.40)	16:47	5.9
Level 40	4(3.14)	4(3.46)	5(4.20)	15:56	5.8
Level 45	4(3.05)	4(3.34)	5(4.02)	15:22	5.8
Level 50	3(2.97)	4(3.24)	4(3.87)	14:54	5.7

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.

4 trainers at level 40

Mewtwo3.14

A prepared party

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

4 trainers at level 40

Mewtwo3.14
Landorus (Therian)3.40
Necrozma (Dusk Mane)3.50
Necrozma (Dawn Wings)3.52
Hoopa (Unbound)3.58
Groudon3.62

A mixed local group

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

5 trainers at level 40

Alakazam4.03
Excadrill4.05
Zamazenta (Crowned Shield)4.08
Metagross4.11
Espeon4.19
Kyurem (Black)4.19

The party these numbers assume

1. Mewtwo

Psycho Cut + Psystrike

2. Landorus (Therian)

Mud Shot + Sandsear Storm

3. Necrozma (Dusk Mane)

Psycho Cut + Sunsteel Strike

4. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

5. Hoopa (Unbound)

Confusion + Psychic

6. Groudon

Mud Shot + Precipice Blades

See the full ranked counter list for Silvally (Poison) · 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.