The rules

How it scores

You're out birding. You see a bird, you photograph it, you add it to your collection. The species gets a tier from how hard it genuinely is to find in your region right now, and the points are yours for the year. Whoever holds the best collection when the season ends wins.

Tiers and points

Common ≥ 150 locations a week10

Regular ≥ 40 locations a week25

Uncommon ≥ 10 locations a week50

Rare ≥ 2 locations a week100

Mega fewer than 2 locations a week250

"Locations a week" is how many distinct places in the region reported the species in a normal week — from eBird's live data for the 28 days before your find, or from a seasonal prior while the data is thin. So a Varied Thrush in a January garden is common; the same bird in August is a different tier. A find's tier is frozen when you add it.

The rules

Once each: Each species counts once per collection per season. A second photo of the same species is refused.
Your find: You found it and you photographed it, this season, inside the league's region.
Season: A calendar year. Photos taken earlier in the year count.
Standings: Total points, then number of species, then the rarest single find.
Year end: Standings freeze on Dec 31 and the leader takes the trophy.

Verification

Points come from a photo, so trust is the whole design. Every find shows exactly which checks it passed.

Camera date: Read from the photo's EXIF. Proves the season. A photo without one is allowed but needs a league-mate to confirm it, whatever the tier.
GPS: Read from the photo. Must fall inside the region; outside is refused. Missing GPS is allowed.
Plausibility: We hold the regional sightings, so we check whether the species is even being reported around that date. A rare or mega claim with no regional reports is flagged for the commissioner and never scores on its own.
League-mates: Rare finds need 1 confirmation; mega finds need 2. Common, regular and uncommon finds with a camera date verify on the spot. You can't confirm your own.
Commissioner: Can clear a flag (it then needs the normal confirmations) or reject a find outright.

Not built yet: automated species identification from the photo. The plan is a vision model as a second opinion, never as the judge.