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 3 to be safe — 2 if everyone is prepared

At level 40, a party of Urshifu (Rapid Strike)'s top six counters needs 1.79 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.03 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:13. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Urshifu (Rapid Strike) · Tier 5

fightingwater

Weak to

flyinggrasselectricpsychicfairy

Boss CP: 45,650
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 Urshifu (Rapid Strike) 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	3(2.39)	3(2.53)	3(2.92)	11:39	6.0
Level 25	3(2.05)	3(2.20)	3(2.52)	10:07	6.0
Level 30	2(1.88)	2(1.98)	3(2.23)	9:06	6.0
Level 35	2(1.74)	2(1.86)	3(2.13)	8:35	5.9
Level 40	2(1.69)	2(1.79)	3(2.03)	8:13	5.9
Level 45	2(1.64)	2(1.73)	2(1.96)	7:58	5.7
Level 50	2(1.60)	2(1.67)	2(1.89)	7:42	5.7

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.

2 trainers at level 40

Mewtwo1.69

A prepared party

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

2 trainers at level 40

Mewtwo1.69
Rayquaza1.69
Enamorus (Incarnate)1.75
Thundurus (Therian)1.83
Galarian Articuno1.87
Tapu Lele1.88

A mixed local group

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

3 trainers at level 40

Zacian (Crowned Sword)1.95
Moltres1.99
Shaymin (Sky)1.98
Zekrom2.00
Yveltal2.00
Tapu Koko2.02

The party these numbers assume

1. Mewtwo

Psycho Cut + Psystrike

2. Rayquaza

Air Slash + Dragon Ascent

3. Enamorus (Incarnate)

Fairy Wind + Fly

4. Thundurus (Therian)

Volt Switch + Wildbolt Storm

5. Galarian Articuno

Psycho Cut + Fly

6. Tapu Lele

Confusion + Nature's Madness

See the full ranked counter list for Urshifu (Rapid Strike) · 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.