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 Mega Lucario's top six counters needs 1.11 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.34 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 5:09. No level in this range makes it soloable with a prepared party. A duo works from level 20.

Mega Lucario · Mega

fightingsteel

Weak to

fightinggroundfire

Boss CP: 42,499
Boss HP: 9,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Mega Lucario 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(1.40)	2(1.76)	3(2.18)	8:12	6.0
Level 25	2(1.19)	2(1.44)	2(1.77)	6:42	6.0
Level 30	2(1.04)	2(1.27)	2(1.54)	5:53	6.0
Level 35	1(0.99)	2(1.17)	2(1.43)	5:26	6.0
Level 40	1(0.95)	2(1.11)	2(1.34)	5:09	6.0
Level 45	1(0.89)	2(1.05)	2(1.29)	4:54	6.0
Level 50	1(0.86)	2(1.02)	2(1.25)	4:44	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.

1 trainer at level 40

Keldeo0.95

A prepared party

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

2 trainers at level 40

Keldeo0.95
Blacephalon1.08
Reshiram1.12
Landorus (Therian)1.14
Terrakion1.17
Blaziken1.17

A mixed local group

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

2 trainers at level 40

Cinderace1.31
Delphox1.30
Conkeldurr1.31
Ho-Oh1.30
Urshifu (Single Strike)1.33
Emboar1.37

The party these numbers assume

1. Keldeo

Low Kick + Secret Sword

2. Blacephalon

Incinerate + Mind Blown

3. Reshiram

Fire Fang + Fusion Flare

4. Landorus (Therian)

Mud Shot + Sandsear Storm

5. Terrakion

Double Kick + Sacred Sword

6. Blaziken

Counter + Aura Sphere

See the full ranked counter list for Mega Lucario · 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.