The Elo number quantifies a player's skill. It was originally invented for chess.
Elo points are used in every Schnopsn game except the training games.

The higher the Elo number of your opponent compared to your own, the more points you get when you win. The lower your opponent's Elo number, the more points you lose when you lose the game.

In case of a schneider (victory/defeat at 0) the won and lost Elo points get increased by half!

In order to appear in the Elo ranking, a player must have played at least 30 Bummerls online, have over 1250 Elo points, have played at least one game within the last 48 hours and played against at least ten different opponents within the last ten days.