Without a time limit, a riichi hanchan is made of the East round followed by the South round. Each round has four base hands, one for each East seat, for eight scheduled hands from East 1 through South 4. In a WRC tournament, a time limit may end the game before that schedule is completed.
East keeps the deal after winning or after being tenpai at an exhaustive draw. One honba is added after an East win and after every exhaustive draw. These repeats extend the hanchan beyond eight hands; South 4 is the final base hand, but it may repeat.
Because a hanchan is roughly twice the length of a tonpu (East-only) game, it rewards patient, positional play: an early deal-in can be recovered, and final standings often turn on the South round. Placement bonuses such as uma are applied to the final scores, so managing your position going into oorasu, not just raw points, is the core skill the format tests.