The Bankers have made Blood Sports available to clones level five and higher. In order to participate, register your LifeNet data with one of the Blood Sports Registrars. These helpful Bankers can be found in all faction towns, central towns such as Trader's Flat, New Flagstaff, Odenville, Embry Crossroads, and Oilville, as well as some of the larger settlements like Watchtower, Sunshine Corners, and Dieseltown.
The Registrar will give you a kit to modify your LifeNet Collar so you can participate in the matches. Once you have made the necessary modifications, you should be able to access the Blood Sports sign up from anywhere in the canyon. To queue up for a Blood Sports match, click the menu button on the lower left of the UI and select 'Blood Sports.' To queue up as a team, the team leader will need to select the match and click 'Join as Team.
Once in a Blood Sports match, click the skull located on the mini map in the right hand corner of the UI to bring up the scoreboard. All participants in a match will receive Death Toll, however winners will receive more points.