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 Alolan Sandshrew's top six counters needs 1.37 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.71 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 6:18. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Alolan Sandshrew · Elite

icesteel

Weak to

fightingfireground

Boss CP: 23,758
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 Alolan Sandshrew 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(1.70)	2(1.94)	3(2.44)	8:57	5.9
Level 25	2(1.52)	2(1.72)	3(2.09)	7:54	5.8
Level 30	2(1.35)	2(1.51)	2(1.88)	6:56	5.7
Level 35	2(1.29)	2(1.43)	2(1.78)	6:35	5.6
Level 40	2(1.25)	2(1.37)	2(1.71)	6:18	5.5
Level 45	2(1.19)	2(1.32)	2(1.64)	6:03	5.4
Level 50	2(1.16)	2(1.27)	2(1.59)	5:50	5.3

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

Keldeo1.25

A prepared party

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

2 trainers at level 40

Keldeo1.25
Blacephalon1.25
Lucario1.38
Reshiram1.41
Terrakion1.45
Blaziken1.47

A mixed local group

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

2 trainers at level 40

Urshifu (Single Strike)1.65
Chandelure1.68
Ho-Oh1.68
Delphox1.68
Emboar1.70
Moltres1.71

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Blacephalon

Incinerate + Mind Blown

3. Lucario

Force Palm + Aura Sphere

4. Reshiram

Fire Fang + Fusion Flare

5. Terrakion

Double Kick + Sacred Sword

6. Blaziken

Counter + Aura Sphere

See the full ranked counter list for Alolan Sandshrew · 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.