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 Vaporeon's top six counters needs 1.72 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.11 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 7:56. No level in this range makes it soloable with a prepared party. A duo works from level 30.

Vaporeon · Tier 5

water

Weak to

grasselectric

Boss CP: 35,745
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 Vaporeon 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(2.58)	3(2.61)	4(3.00)	12:00	6.0
Level 25	3(2.25)	3(2.17)	3(2.62)	10:00	6.0
Level 30	2(1.99)	2(1.92)	3(2.31)	8:51	6.0
Level 35	2(1.78)	2(1.81)	3(2.20)	8:20	5.9
Level 40	2(1.63)	2(1.72)	3(2.11)	7:56	5.9
Level 45	2(1.55)	2(1.65)	3(2.03)	7:36	5.8
Level 50	2(1.51)	2(1.58)	2(1.96)	7:17	5.8

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.

2 trainers at level 40

Regieleki1.63

A prepared party

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

2 trainers at level 40

Regieleki1.63
Kartana1.72
Zeraora1.74
Zekrom1.74
Xurkitree1.74
Thundurus (Therian)1.76

A mixed local group

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

3 trainers at level 40

Roserade2.03
Raikou2.05
Electivire2.07
Chesnaught2.08
Tapu Bulu2.08
Decidueye2.12

The party these numbers assume

1. Regieleki

Lock-On + Thunder Cage

2. Kartana

Razor Leaf + Leaf Blade

3. Zeraora

Volt Switch + Plasma Fists

4. Zekrom

Charge Beam + Fusion Bolt

5. Xurkitree

Thunder Shock + Discharge

6. Thundurus (Therian)

Volt Switch + Wildbolt Storm

See the full ranked counter list for Vaporeon · 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.