How movement works in Up and Down the River
Movement is decided by one thing: did you win your match. It is applied when you generate the next round, not when you enter the score.
The basic rule
Win → move up one court
Lose → move down one court
Both players on the winning side move up together. In the set-partners variant the pair moves as a unit; in the individual variant the two players who happened to be partnered that round both move, then get re-paired on their new court.
You never move more than one court in a round, however convincingly you win.
The edges
Three cases where the basic rule cannot apply as written:
Top court, winner — stays on the top court. There is nothing above it.
Top court, loser — drops to Court 2. Not to the bottom. Losing on Court 1 costs exactly one court, the same as everywhere else.
Bottom court, loser — stays on the bottom court, unless there is a bye group to swap with.
The top-court-loser rule is the one hosts most often expect to work differently. Some real-world versions of this game send the top-court loser all the way to the bottom. This one does not.
Byes and the bottom court
When the roster does not divide into fours, the leftover players form a bye group.
Bottom-court losers swap with the bye players, which is what keeps the bye rotating rather than parking the same people out week after week.
When there is only one real court, bye rotation takes priority — losers swap with the bye group rather than trying to move to a court that does not exist.
For how byes are chosen, see Bye Mode for Ladder Leagues.
Nothing moves until the round is scored
Movement comes from results. If a round has not been scored, generating the next one has nothing to act on.
Score the round first, then generate.