Speed tiers
Champions has no IVs and no EVs: every Pokémon behaves as IV 31, and EVs are replaced by stat points, at most 32 per stat and 66 in all. The level is always 50. So speed is floor((base + 20 + points) x nature) — a short formula everybody gets wrong, because the +20 goes in before the nature.
How this works
And on the other side:
How many points does it take to outspeed one particular target?