How this tier list works
This is an analytical base-stat tier list, not a playtested win-rate ranking. For each Pokémon, we calculate its percentile among the 966 playable partners in attack multiplier, HP and movement speed. The score is the mean of those three percentiles. S means score ≥80; A ≥65; B ≥50; C is below 50. A displayed percentile uses the fraction of partners with a strictly smaller value.
How to use the ranking
Pick a role before chasing the largest score. HP gives more room for mistakes, speed helps reposition, and attack multiplies move damage. Starting attacks, type matchups, weather, held items, permanent upgrades and your ability to dodge can reverse a base-stat comparison.
Do not confuse rarity with a legendary encounter
Five stars is a gacha rarity. A Pokémon with the legendary flag is separately eligible for a rift encounter. The executable regional pool includes any matching generation and rarity with a supported sprite; it does not exclude the legendary flag.
A worked ranking example
Eternatus scores 97.86 with 133 HP, 133 speed and ×1.50 attack; Mewtwo scores 96.65 with 118 HP, 133 speed and ×1.55 attack. Both are S in this base-stat method. Eternatus has more HP; Mewtwo more attack. The score cannot prove one has a higher practical win rate.