#4. Its what made League and Dota 2 famous, its system is what makes people come back to keep playing and climb the ranks. The usual and only down side I can think of are the smurf/second accounts by pro sparrers who'll take advantage of #4 system. The current and the old system werent that good imo. Pretty sure some old sparrers from before would agree we were fine way before a leaderboard system showed up