Each player in Sniper 3D has a number attached to their account, called Elo rating. This rating varies according to your PvP match results. It takes into consideration the ratings of the players that you're winning or losing to, plus it matches you to opponents with a similar Elo rating.

This will also reflect on the way that you'll win PvP points, so if you lose to a player with a slightly high Elo rating, only a few PvP points will be taken from you. However, if you defeat them you'll also get a better reward. This makes sure that you are reward fairly based on the strength of the opponent you face.