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 3 to be safe — 3 if everyone is prepared

At level 40, a party of Krabby's top six counters needs 2.35 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 2.88 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 11:07. No level in this range makes it soloable with a prepared party.

Krabby · Shadow Tier 5

water

Weak to

grasselectric

Boss CP: 28,301
Boss HP: 15,000
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Krabby 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	4(3.59)	4(3.53)	5(4.09)	16:40	6.0
Level 25	4(3.06)	3(2.98)	4(3.52)	14:04	6.0
Level 30	3(2.64)	3(2.64)	4(3.18)	12:27	6.0
Level 35	3(2.50)	3(2.51)	4(3.04)	11:51	6.0
Level 40	3(2.22)	3(2.35)	3(2.88)	11:07	6.0
Level 45	3(2.18)	3(2.29)	3(2.77)	10:49	5.9
Level 50	3(2.14)	3(2.20)	3(2.70)	10:24	5.9

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

Regieleki2.22

A prepared party

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

3 trainers at level 40

Regieleki2.22
Kartana2.34
Zeraora2.34
Xurkitree2.37
Thundurus (Therian)2.39
Zekrom2.47

A mixed local group

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

3 trainers at level 40

Kyurem (Black)2.78
Roserade2.79
Raikou2.82
Zapdos2.84
Tapu Bulu2.85
Necrozma (Dawn Wings)2.85

The party these numbers assume

1. Regieleki

Thunder Shock + Thunder Cage

2. Kartana

Razor Leaf + Leaf Blade

3. Zeraora

Spark + Plasma Fists

4. Xurkitree

Thunder Shock + Discharge

5. Thundurus (Therian)

Volt Switch + Wildbolt Storm

6. Zekrom

Charge Beam + Fusion Bolt

See the full ranked counter list for Krabby · 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.