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 2 to be safe — 1 if everyone is prepared

At level 40, a party of Beldum's top six counters needs 0.94 trainers (round up: 1), and a mixed lobby of ranks 13-24 needs 1.11 (round up: 2). The raid timer is 180 seconds and one prepared trainer alone would take 2:44. A prepared solo becomes possible at level 35. A duo works from level 20.

Beldum · Shadow Tier 3

steelpsychic

Weak to

groundghostfiredark

Boss CP: 8,511
Boss HP: 4,000
Raid timer: 180s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Beldum 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	2(1.16)	2(1.31)	2(1.56)	3:49	4.7
Level 25	1(0.97)	2(1.13)	2(1.35)	3:19	3.7
Level 30	1(0.87)	2(1.01)	2(1.23)	2:57	3.0
Level 35	1(0.84)	1(0.97)	2(1.17)	2:50	2.7
Level 40	1(0.82)	1(0.94)	2(1.11)	2:44	2.4
Level 45	1(0.78)	1(0.91)	2(1.09)	2:39	2.2
Level 50	1(0.75)	1(0.87)	2(1.05)	2:32	1.8

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.

1 trainer at level 40

Blacephalon0.82

A prepared party

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

1 trainer at level 40

Blacephalon0.82
Necrozma (Dawn Wings)0.83
Reshiram0.95
Landorus (Therian)0.97
Chandelure1.03
Darkrai1.02

A mixed local group

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

2 trainers at level 40

Blaziken1.09
Hydreigon1.08
Tyranitar1.08
Gengar1.09
Ho-Oh1.10
Moltres1.12

The party these numbers assume

1. Blacephalon

Astonish + Mind Blown

2. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

3. Reshiram

Fire Fang + Fusion Flare

4. Landorus (Therian)

Mud Shot + Sandsear Storm

5. Chandelure

Fire Spin + Shadow Ball

6. Darkrai

Snarl + Foul Play

See the full ranked counter list for Beldum · 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.