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 4 to be safe — 4 if everyone is prepared

At level 40, a party of Vikavolt's top six counters needs 3.09 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 3.53 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 14:14. No level in this range makes it soloable with a prepared party.

Vikavolt · Elite

bugelectric

Weak to

rockfire

Boss CP: 50,036
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 Vikavolt 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	5(4.07)	5(4.89)	6(5.68)	22:31	6.0
Level 25	4(3.45)	5(4.08)	5(4.77)	18:46	6.0
Level 30	4(3.08)	4(3.53)	5(4.04)	16:14	6.0
Level 35	3(2.90)	4(3.27)	4(3.76)	15:03	6.0
Level 40	3(2.81)	4(3.09)	4(3.53)	14:14	6.0
Level 45	3(2.66)	3(2.98)	4(3.38)	13:42	6.0
Level 50	3(2.64)	3(2.85)	4(3.26)	13:08	5.9

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.

3 trainers at level 40

Reshiram2.81

A prepared party

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

4 trainers at level 40

Reshiram2.81
Blacephalon2.91
Heatran3.13
Eternatus3.19
Glimmora3.23
Rampardos3.28

A mixed local group

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

4 trainers at level 40

Volcarona3.50
Kyurem (Black)3.51
Necrozma (Dawn Wings)3.52
Tyrantrum3.47
Moltres3.53
Terrakion3.53

The party these numbers assume

1. Reshiram

Fire Fang + Fusion Flare

2. Blacephalon

Incinerate + Mind Blown

3. Heatran

Fire Spin + Magma Storm

4. Eternatus

Poison Jab + Dynamax Cannon

5. Glimmora

Rock Throw + Meteor Beam

6. Rampardos

Smack Down + Rock Slide

See the full ranked counter list for Vikavolt · 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.