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 Scream Tail's top six counters needs 3.29 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 4.50 (round up: 5). The raid timer is 300 seconds and one prepared trainer alone would take 15:08. No level in this range makes it soloable with a prepared party.

Scream Tail · Elite

fairypsychic

Weak to

poisonghoststeel

Boss CP: 34,366
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 Scream Tail 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	4(3.86)	5(4.40)	7(6.01)	20:14	3.5
Level 25	4(3.33)	4(3.91)	6(5.36)	17:59	2.8
Level 30	4(3.15)	4(3.56)	5(4.89)	16:22	2.3
Level 35	3(2.89)	4(3.39)	5(4.64)	15:37	2.1
Level 40	3(2.81)	4(3.29)	5(4.50)	15:08	1.9
Level 45	3(2.74)	4(3.16)	5(4.34)	14:33	1.7
Level 50	3(2.68)	4(3.10)	5(4.22)	14:16	1.7

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.

3 trainers at level 40

Zacian (Crowned Sword)2.81

A prepared party

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

4 trainers at level 40

Zacian (Crowned Sword)2.81
Necrozma (Dusk Mane)2.93
Zamazenta (Crowned Shield)3.06
Necrozma (Dawn Wings)3.11
Blacephalon3.79
Eternatus4.04

A mixed local group

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

5 trainers at level 40

Naganadel4.25
Dragapult4.38
Nihilego4.45
Dialga4.48
Tinkaton4.50
Dialga (Origin)4.53

The party these numbers assume

1. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

2. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

3. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

4. Necrozma (Dawn Wings)

Metal Claw + Moongeist Beam

5. Blacephalon

Astonish + Shadow Ball

6. Eternatus

Poison Jab + Sludge Bomb

See the full ranked counter list for Scream Tail · 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.