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 2 to be safe — 2 if everyone is prepared

At level 40, a party of Trumbeak's top six counters needs 1.05 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.34 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 4:50. A prepared solo becomes possible at level 50. A duo works from level 20.

Trumbeak · Tier 5

normalflying

Weak to

rockelectricice

Boss CP: 22,853
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 Trumbeak 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	2(1.36)	2(1.52)	2(1.88)	7:00	6.0
Level 25	2(1.18)	2(1.30)	2(1.64)	5:59	6.0
Level 30	2(1.04)	2(1.15)	2(1.47)	5:18	6.0
Level 35	1(1.00)	2(1.09)	2(1.39)	5:02	6.0
Level 40	1(0.96)	2(1.05)	2(1.34)	4:50	6.0
Level 45	1(0.93)	2(1.02)	2(1.28)	4:41	5.9
Level 50	1(0.90)	1(0.97)	2(1.24)	4:29	5.6

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

Kyurem (White)0.96

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)0.96
Regieleki1.01
Kyurem (Black)1.06
Thundurus (Therian)1.07
Zeraora1.09
Xurkitree1.11

A mixed local group

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

2 trainers at level 40

Electivire1.28
Gigalith1.29
Raikou1.30
Rhyperior1.32
Tyrantrum1.33
Magnezone1.32

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Regieleki

Lock-On + Thunder Cage

3. Kyurem (Black)

Dragon Tail + Freeze Shock

4. Thundurus (Therian)

Volt Switch + Wildbolt Storm

5. Zeraora

Volt Switch + Plasma Fists

6. Xurkitree

Thunder Shock + Discharge

See the full ranked counter list for Trumbeak · 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.