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 1 to be safe — 1 if everyone is prepared

At level 40, a party of Cranidos's top six counters needs 0.70 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.94 (round up: 1). The raid timer is 300 seconds and one prepared trainer alone would take 3:13. A prepared solo becomes possible at level 25. A duo works from level 20.

Cranidos · Tier 5

rock

Weak to

fightinggroundsteelwatergrass

Boss CP: 26,463
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 Cranidos 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	1(0.91)	2(1.01)	2(1.35)	4:38	5.7
Level 25	1(0.77)	1(0.86)	2(1.16)	3:59	5.4
Level 30	1(0.68)	1(0.76)	2(1.03)	3:31	4.8
Level 35	1(0.65)	1(0.73)	1(0.98)	3:22	4.5
Level 40	1(0.62)	1(0.70)	1(0.94)	3:13	4.1
Level 45	1(0.59)	1(0.68)	1(0.91)	3:07	3.8
Level 50	1(0.57)	1(0.65)	1(0.87)	3:00	3.4

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

Zacian (Crowned Sword)0.62

A prepared party

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

1 trainer at level 40

Zacian (Crowned Sword)0.62
Zamazenta (Crowned Shield)0.62
Necrozma (Dusk Mane)0.65
Keldeo0.70
Lucario0.78
Terrakion0.82

A mixed local group

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

1 trainer at level 40

Urshifu (Single Strike)0.92
Kyogre0.93
Groudon0.92
Hisuian Decidueye0.93
Urshifu (Rapid Strike)0.93
Zarude0.94

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. Terrakion

Double Kick + Sacred Sword

See the full ranked counter list for Cranidos · 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.