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 1 to be safe — 1 if everyone is prepared

At level 40, a party of Giratina (Altered)'s top six counters needs 0.15 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 0.20 (round up: 1). The raid timer is 180 seconds and one prepared trainer alone would take 0:27. A prepared solo becomes possible at level 20. A duo works from level 20.

Giratina (Altered) · Shadow Tier 1

ghostdragon

Weak to

ghosticedragondarkfairy

Boss CP: 7,665
Boss HP: 600
Raid timer: 180s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Giratina (Altered) 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	1(0.20)	1(0.22)	1(0.29)	0:40	1.1
Level 25	1(0.16)	1(0.19)	1(0.25)	0:34	0.5
Level 30	1(0.14)	1(0.17)	1(0.23)	0:31	0.2
Level 35	1(0.13)	1(0.16)	1(0.21)	0:29	0.1
Level 40	1(0.13)	1(0.15)	1(0.20)	0:27	0.1
Level 45	1(0.13)	1(0.15)	1(0.19)	0:26	0.1
Level 50	1(0.13)	1(0.15)	1(0.19)	0:26	0.0

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.

1 trainer at level 40

Eternatus0.13

A prepared party

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

1 trainer at level 40

Eternatus0.13
Kyurem (Black)0.14
Necrozma (Dawn Wings)0.15
Kyurem (White)0.16
Palkia (Origin)0.16
Dialga (Origin)0.17

A mixed local group

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

1 trainer at level 40

Darkrai0.19
Salamence0.19
Blacephalon0.19
Zekrom0.19
Dialga0.20
Hisuian Zoroark0.20

The party these numbers assume

1. Eternatus

Dragon Tail + Dynamax Cannon

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Necrozma (Dawn Wings)

Shadow Claw + Moongeist Beam

4. Kyurem (White)

Dragon Breath + Ice Burn

5. Palkia (Origin)

Dragon Tail + Spacial Rend

6. Dialga (Origin)

Dragon Breath + Roar of Time

See the full ranked counter list for Giratina (Altered) · 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.