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 13 to be safe — 7 if everyone is prepared

At level 40, a party of Shuckle's top six counters needs 6.28 trainers (round up: 7), and a mixed lobby of ranks 13-24 needs 12.86 (round up: 13). The raid timer is 300 seconds and one prepared trainer alone would take 28:55. No level in this range makes it soloable with a prepared party.

Shuckle · Elite

bugrock

Weak to

rocksteelwater

Boss CP: 9,174
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 Shuckle 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	7(6.21)	9(8.20)	14(13.04)	37:45	2.1
Level 25	6(5.75)	8(7.30)	14(13.03)	33:34	1.3
Level 30	5(4.86)	7(6.75)	13(12.97)	31:04	1.2
Level 35	5(4.74)	7(6.45)	13(12.95)	29:40	1.0
Level 40	5(4.63)	7(6.28)	13(12.86)	28:55	0.9
Level 45	5(4.55)	7(6.01)	13(12.52)	27:39	0.9
Level 50	5(4.46)	6(5.77)	13(12.21)	26:33	0.8

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.

5 trainers at level 40

Necrozma (Dusk Mane)4.63

A prepared party

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

7 trainers at level 40

Necrozma (Dusk Mane)4.63
Zacian (Crowned Sword)4.71
Zamazenta (Crowned Shield)5.04
Metagross6.44
Lucario8.33
Aggron8.55

A mixed local group

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

13 trainers at level 40

Hydreigon11.87
Espeon12.45
Magneton12.60
Kingler13.04
Poliwrath13.04
Mew13.04

The party these numbers assume

1. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

2. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

3. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

4. Metagross

Fury Cutter + Meteor Mash

5. Lucario

Counter + Meteor Mash

6. Aggron

Metal Sound + Meteor Beam

See the full ranked counter list for Shuckle · 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.