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 Staravia's top six counters needs 1.78 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.25 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:25. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Staravia · Shadow Tier 5

normalflying

Weak to

rockelectricice

Boss CP: 20,075
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 Staravia 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(2.27)	3(2.60)	4(3.28)	12:18	6.0
Level 25	3(2.01)	3(2.25)	3(2.79)	10:37	6.0
Level 30	2(1.76)	2(1.98)	3(2.49)	9:21	6.0
Level 35	2(1.68)	2(1.89)	3(2.35)	8:55	6.0
Level 40	2(1.61)	2(1.78)	3(2.25)	8:25	6.0
Level 45	2(1.56)	2(1.72)	3(2.18)	8:09	6.0
Level 50	2(1.50)	2(1.66)	3(2.10)	7:51	6.0

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

Kyurem (White)1.61

A prepared party

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

2 trainers at level 40

Kyurem (White)1.61
Regieleki1.74
Kyurem (Black)1.77
Thundurus (Therian)1.83
Zeraora1.86
Xurkitree1.89

A mixed local group

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

3 trainers at level 40

Zacian (Crowned Sword)2.17
Gigalith2.20
Rhyperior2.20
Necrozma (Dusk Mane)2.21
Raikou2.22
Tyrantrum2.23

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Regieleki

Thunder Shock + Thunder Cage

3. Kyurem (Black)

Dragon Tail + Freeze Shock

4. Thundurus (Therian)

Volt Switch + Wildbolt Storm

5. Zeraora

Spark + Plasma Fists

6. Xurkitree

Thunder Shock + Discharge

See the full ranked counter list for Staravia · 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.