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 — 3 if everyone is prepared

At level 40, a party of Swellow's top six counters needs 2.30 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 2.94 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 10:53. No level in this range makes it soloable with a prepared party.

Swellow · Shadow Tier 5

normalflying

Weak to

rockelectricice

Boss CP: 28,879
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 Swellow 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	4(3.03)	4(3.43)	5(4.27)	16:12	6.0
Level 25	3(2.56)	3(2.88)	4(3.65)	13:35	6.0
Level 30	3(2.31)	3(2.56)	4(3.23)	12:07	6.0
Level 35	3(2.19)	3(2.43)	4(3.07)	11:28	6.0
Level 40	3(2.12)	3(2.30)	3(2.94)	10:53	6.0
Level 45	3(2.01)	3(2.21)	3(2.80)	10:27	6.0
Level 50	2(1.93)	3(2.13)	3(2.70)	10:04	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.

3 trainers at level 40

Kyurem (White)2.12

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)2.12
Regieleki2.20
Kyurem (Black)2.36
Zeraora2.36
Thundurus (Therian)2.38
Xurkitree2.41

A mixed local group

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

3 trainers at level 40

Necrozma (Dusk Mane)2.82
Zapdos2.84
Raikou2.85
Rhyperior2.87
Magnezone2.90
Zacian (Crowned Sword)2.90

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Regieleki

Lock-On + Thunder Cage

3. Kyurem (Black)

Dragon Tail + Freeze Shock

4. Zeraora

Spark + Plasma Fists

5. Thundurus (Therian)

Volt Switch + Wildbolt Storm

6. Xurkitree

Thunder Shock + Discharge

See the full ranked counter list for Swellow · 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.