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 — 3 if everyone is prepared

At level 40, a party of Shaymin (Sky)'s top six counters needs 2.33 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.04 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 10:43. No level in this range makes it soloable with a prepared party.

Shaymin (Sky) · Elite

grassflying

Weak to

iceflyingpoisonrockfire

Boss CP: 52,512
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 Shaymin (Sky) 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(2.57)	4(3.65)	5(4.76)	16:48	6.0
Level 25	2(1.99)	3(2.98)	4(3.94)	13:42	6.0
Level 30	2(1.77)	3(2.61)	4(3.46)	12:00	6.0
Level 35	2(1.66)	3(2.48)	4(3.22)	11:25	6.0
Level 40	2(1.61)	3(2.33)	4(3.04)	10:43	6.0
Level 45	2(1.56)	3(2.25)	3(2.92)	10:21	6.0
Level 50	2(1.50)	3(2.15)	3(2.79)	9:54	6.0

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

Kyurem (White)1.61

A prepared party

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

3 trainers at level 40

Kyurem (White)1.61
Kyurem (Black)2.07
Baxcalibur2.29
Rayquaza2.60
Eternatus2.68
Cetitan2.72

A mixed local group

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

4 trainers at level 40

Avalugg2.92
Zamazenta (Crowned Shield)2.93
Articuno2.94
Vanilluxe2.99
Moltres3.02
Genesect (Chill)3.04

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Baxcalibur

Ice Fang + Avalanche

4. Rayquaza

Air Slash + Dragon Ascent

5. Eternatus

Poison Jab + Dynamax Cannon

6. Cetitan

Ice Shard + Avalanche

See the full ranked counter list for Shaymin (Sky) · 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.