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 4 to be safe — 4 if everyone is prepared

At level 40, a party of Mega Lucario's top six counters needs 3.12 trainers (round up: 4), and a mixed lobby of ranks 13-24 needs 3.80 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 14:22. No level in this range makes it soloable with a prepared party.

Mega Lucario · Super Mega

fightingsteel

Weak to

fightinggroundfire

Boss CP: 70,832
Boss HP: 25,000
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	5(4.00)	6(5.15)	7(6.03)	23:43	6.0
Level 25	4(3.38)	5(4.16)	5(4.92)	19:09	6.0
Level 30	3(2.93)	4(3.63)	5(4.26)	16:41	6.0
Level 35	3(2.80)	4(3.30)	5(4.02)	15:12	6.0
Level 40	3(2.71)	4(3.12)	4(3.80)	14:22	6.0
Level 45	3(2.52)	3(2.97)	4(3.64)	13:41	6.0
Level 50	3(2.44)	3(2.86)	4(3.49)	13:09	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

Keldeo2.71

A prepared party

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

4 trainers at level 40

Keldeo2.71
Blacephalon3.06
Reshiram3.17
Landorus (Therian)3.22
Terrakion3.28
Blaziken3.28

A mixed local group

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

4 trainers at level 40

Ho-Oh3.65
Groudon3.70
Delphox3.72
Conkeldurr3.71
Emboar3.76
Urshifu (Single Strike)3.90

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.