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 Silvally (Water)'s top six counters needs 2.00 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.52 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 9:11. No level in this range makes it soloable with a prepared party. A duo works from level 40.

Silvally (Water) · Tier 5

water

Weak to

grasselectric

Boss CP: 38,072
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 Silvally (Water) 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	3(2.86)	3(2.94)	4(3.60)	13:31	6.0
Level 25	3(2.33)	3(2.47)	4(3.11)	11:21	6.0
Level 30	3(2.06)	3(2.21)	3(2.75)	10:09	5.9
Level 35	2(1.93)	3(2.10)	3(2.63)	9:39	5.9
Level 40	2(1.86)	2(2.00)	3(2.52)	9:11	5.7
Level 45	2(1.79)	2(1.93)	3(2.44)	8:52	5.6
Level 50	2(1.71)	2(1.86)	3(2.35)	8:34	5.4

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

Regieleki1.86

A prepared party

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

2 trainers at level 40

Regieleki1.86
Thundurus (Therian)1.98
Zeraora2.01
Xurkitree2.02
Kartana2.04
Zekrom2.07

A mixed local group

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

3 trainers at level 40

Raikou2.41
Kyurem (Black)2.46
Magnezone2.48
Roserade2.49
Meowscarada2.52
Zapdos2.53

The party these numbers assume

1. Regieleki

Lock-On + Thunder Cage

2. Thundurus (Therian)

Volt Switch + Wildbolt Storm

3. Zeraora

Volt Switch + Plasma Fists

4. Xurkitree

Thunder Shock + Discharge

5. Kartana

Razor Leaf + Leaf Blade

6. Zekrom

Charge Beam + Fusion Bolt

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