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 Rockruff's top six counters needs 1.25 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.67 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 5:46. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Rockruff · Elite

rock

Weak to

fightinggroundsteelwatergrass

Boss CP: 18,002
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 Rockruff 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(1.50)	2(1.74)	3(2.35)	8:01	5.8
Level 25	2(1.34)	2(1.52)	3(2.07)	6:59	5.5
Level 30	2(1.20)	2(1.37)	2(1.84)	6:17	5.0
Level 35	2(1.13)	2(1.30)	2(1.75)	6:00	4.9
Level 40	2(1.10)	2(1.25)	2(1.67)	5:46	4.7
Level 45	2(1.05)	2(1.21)	2(1.61)	5:34	4.4
Level 50	2(1.02)	2(1.16)	2(1.56)	5:21	4.2

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

Zacian (Crowned Sword)1.10

A prepared party

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

2 trainers at level 40

Zacian (Crowned Sword)1.10
Zamazenta (Crowned Shield)1.12
Necrozma (Dusk Mane)1.16
Keldeo1.27
Lucario1.40
Kartana1.46

A mixed local group

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

2 trainers at level 40

Hisuian Decidueye1.65
Kyogre1.66
Groudon1.65
Conkeldurr1.66
Xurkitree1.67
Breloom1.67

The party these numbers assume

1. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

2. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

3. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

4. Keldeo

Low Kick + Secret Sword

5. Lucario

Force Palm + Aura Sphere

6. Kartana

Razor Leaf + Sacred Sword

See the full ranked counter list for Rockruff · 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.