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 — 2 if everyone is prepared

At level 40, a party of Yveltal's top six counters needs 1.95 trainers (round up: 2), and a mixed lobby of ranks 13-24 needs 2.43 (round up: 3). The raid timer is 300 seconds and one prepared trainer alone would take 8:58. No level in this range makes it soloable with a prepared party. A duo works from level 40.

Yveltal · Tier 5

darkflying

Weak to

rockelectricicefairy

Boss CP: 45,899
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 Yveltal 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(2.72)	4(3.19)	4(3.88)	14:40	6.0
Level 25	3(2.36)	3(2.60)	4(3.19)	11:59	6.0
Level 30	2(1.91)	3(2.25)	3(2.78)	10:21	6.0
Level 35	2(1.81)	3(2.08)	3(2.59)	9:36	6.0
Level 40	2(1.75)	2(1.95)	3(2.43)	8:58	6.0
Level 45	2(1.65)	2(1.88)	3(2.34)	8:38	6.0
Level 50	2(1.59)	2(1.82)	3(2.24)	8:24	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

Kyurem (White)1.75

A prepared party

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

2 trainers at level 40

Kyurem (White)1.75
Kyurem (Black)1.92
Regieleki1.96
Zeraora1.99
Zacian (Crowned Sword)2.02
Thundurus (Therian)2.04

A mixed local group

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

3 trainers at level 40

Electivire2.29
Enamorus (Incarnate)2.29
Rhyperior2.34
Raikou2.41
Gigalith2.42
Zapdos2.40

The party these numbers assume

1. Kyurem (White)

Ice Fang + Ice Burn

2. Kyurem (Black)

Dragon Tail + Freeze Shock

3. Regieleki

Thunder Shock + Thunder Cage

4. Zeraora

Spark + Plasma Fists

5. Zacian (Crowned Sword)

Metal Claw + Play Rough

6. Thundurus (Therian)

Volt Switch + Wildbolt Storm

See the full ranked counter list for Yveltal · 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.