I believe adding a leaderboard system of any sort would motivate players to strive to the top. The type I suggest would be # of kills/wins in a 6+ person room. So basically don't count any matches with 5 people or under to prevent cheating/abuse of such a stat. Also, let's take an example from Fortnite Tracker using some of the statistics they use to rank players. For score per match, you could do the same for Rumble Fighter with the points on the scoreboard screen. This will obviously be the average points the player gets. Instead of top 25, you could do top 3. For the win%, you could just keep the same conditions as mentioned in the first paragraph, and count it. I myself just want something to strive for in this game, it would settle some debate and not to mention give others another reason for playing. So pretty much just make a top 20 list of players with one of the stats, I would be happy with that.