Some players may notice they receive a different rank than the rank previously held by their opponent. This occurs in the rare situation that you have targeted an opponent who is also currently fighting a battle arena match that has caused their rank to change, or when someone has challenged you and won at the same time that you won against someone else. In these situations, you may find yourself in a different rank than expected.
The Battle Arena Leaderboards work on a rank swap system, meaning that rather than gaining points to move you position up the leaderboard one spot at a time, you claim the current rank of those that you defeat, and they take your place.
Let's say, for example, you are rank 52 and you challenge rank 30. Unbeknownst to yourself, that rank 30 player challenged rank 1 just before your challenge and, just before you beat the rank 30, they beat rank 1, moving your position. Since you then beat them, even if just a split second later, you swap places and are now rank 1.
For this same reason, it is possible for your rank to decrease abruptly. If a rank 120 for example challenges a rank 60, who challenges, 30, who challenges 1 and everyone wins in just the right order, you can go from 1 right back down to 120 as it is a "swap" and not a climb. You switch positions with the person you beat.
If your game client is at all out of sync with the game server, it is possible that the game might display a rank that is not fully up-to-date. For best results, view your rank immediately after restarting your app.