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 Skarmory's top six counters needs 1.44 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 1.84 (round up: 2). The raid timer is 300 seconds and one prepared trainer alone would take 6:42. No level in this range makes it soloable with a prepared party. A duo works from level 25.

Mega Skarmory · Mega

steelflying

Weak to

fireelectric

Boss CP: 42,590
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 Skarmory 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	3(2.19)	3(2.22)	3(2.89)	10:21	6.0
Level 25	2(1.99)	2(1.90)	3(2.45)	8:50	6.0
Level 30	2(1.79)	2(1.64)	3(2.08)	7:36	6.0
Level 35	2(1.57)	2(1.52)	2(1.94)	7:05	6.0
Level 40	2(1.37)	2(1.44)	2(1.84)	6:42	6.0
Level 45	2(1.33)	2(1.38)	2(1.74)	6:26	6.0
Level 50	2(1.30)	2(1.35)	2(1.68)	6:17	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.

2 trainers at level 40

Regieleki1.37

A prepared party

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

2 trainers at level 40

Regieleki1.37
Xurkitree1.42
Thundurus (Therian)1.44
Zeraora1.45
Reshiram1.47
Zekrom1.51

A mixed local group

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

2 trainers at level 40

Victini1.76
Moltres1.74
Cinderace1.77
Kyurem (White)1.80
Kyurem (Black)1.83
Delphox1.83

The party these numbers assume

1. Regieleki

Thunder Shock + Thunder Cage

2. Xurkitree

Thunder Shock + Discharge

3. Thundurus (Therian)

Volt Switch + Wildbolt Storm

4. Zeraora

Spark + Plasma Fists

5. Reshiram

Fire Fang + Fusion Flare

6. Zekrom

Charge Beam + Fusion Bolt

See the full ranked counter list for Mega Skarmory · 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.