Using only your fists, you must down 20 players total. It might sound easy, but it takes time throughout several matches. Best way to do this is to take out AFK players. Doing this requires you to stay on the plane and jump out at the end and get ready to take out those AFK players, if there are any, and attack them when they land on the ground, with little resistance from them. Be wary that active players are aware of this too and might be farming for easy kills, so you might get gunned down soon after landing. This is why you should leave the plane a few seconds before the AFK players are dropped. You can also arm yourself and take out any other active players around and then press X to holster your weapon and punch the daylight out of the AFK players. You can also try land near another player who also just landed with a parachute and chase after them, some players might focus on finding a weapon to take you down and require to reload if it is a gun. Use this to your advantage. When jumping and pressing the mouse key to punch, you land a hitting strike, which does alot of damage. This is useful in both scenarios, with a player rushing for a gun or an AFK player, since there might be another active player nearby approaching to take you and the AFK players down with a gun. Jump striking makes it much faster to kill the AFK player then.