The leaderboard comes in three scales: worldwide, by country and by region. It lists players who have an account — a game played as a guest leaves no trace — and anyone can opt out at any time without losing their progress.
Ranked games have a measure of their own, a strength rating rather than a tally of wins. Everyone starts at 1000 points and plays five placement games, during which the rating moves twice as fast, before it settles. The rating never falls below 100: a bad run costs you places, it does not erase months of play.
Six tiers mark out the scale: Bronze, then Silver from 900, Gold at 1050, Platinum at 1200, Diamond at 1350 and Master at 1500. Ranked games open at level 10 — long enough to have learned the rules, and to keep an account created for a single game from skewing everyone else’s rating.
A leaderboard measures consistency, not one lucky evening. A win against a higher-rated player is worth more than a win against a beginner, and the reverse holds too: that is what stops anyone from climbing by picking their opponents.