By clicking on this icon you can see who the Best Players are and what your ranking is among all players. The classification is based on the number of Coins each player has won on a daily, weekly, or monthly basis. The more active player you are, the higher you will be ranked among the Best Players. This depends on the number of your victories and your Game Mode.
IMPORTANT NOTE: Since the classification is based on won Coins, the players that participate in the higher Game Modes climb faster on the Leaderboards.

To avoid "cheating" the following rule applies: If you play during the same day with the same opponent, you cannot bet more Coins. The same happens if you play with the friends you invite in order to eliminate the possibility of earning Coins in multiple batches with fake friends