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 — 2 if everyone is prepared

At level 40, a party of Dreepy's top six counters needs 1.00 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.29 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 4:36. A prepared solo becomes possible at level 45. A duo works from level 20.

Dreepy · Elite

dragonghost

Weak to

ghosticedragondarkfairy

Boss CP: 16,274
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 Dreepy 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(1.19)	2(1.37)	2(1.77)	6:17	5.5
Level 25	2(1.05)	2(1.20)	2(1.56)	5:33	4.7
Level 30	1(0.94)	2(1.09)	2(1.41)	5:01	3.7
Level 35	1(0.90)	2(1.03)	2(1.35)	4:44	3.3
Level 40	1(0.88)	2(1.00)	2(1.29)	4:36	3.0
Level 45	1(0.85)	1(0.97)	2(1.25)	4:27	2.7
Level 50	1(0.83)	1(0.94)	2(1.21)	4:18	2.4

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

Eternatus0.88

A prepared party

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

2 trainers at level 40

Eternatus0.88
Kyurem (Black)0.92
Necrozma (Dawn Wings)0.95
Kyurem (White)1.04
Palkia (Origin)1.10
Baxcalibur1.12

A mixed local group

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

2 trainers at level 40

Darkrai1.25
Dragapult1.25
Garchomp1.25
Zacian (Crowned Sword)1.27
Regidrago1.28
Dragonite1.29

The party these numbers assume

1. Eternatus

Dragon Tail + Dynamax Cannon

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Necrozma (Dawn Wings)

Psycho Cut + Moongeist Beam

4. Kyurem (White)

Ice Fang + Ice Burn

5. Palkia (Origin)

Dragon Tail + Spacial Rend

6. Baxcalibur

Ice Fang + Glaive Rush

See the full ranked counter list for Dreepy · 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.