The service rules in badminton are among the most precise in any racket sport — and the most frequently misunderstood by recreational players. Since the Badminton World Federation (BWF) adopted rally point scoring in 2006, the server's court position is directly determined by their current score: even scores (0, 2, 4, 6…) mean serving from the right service court; odd scores (1, 3, 5…) mean serving from the left. This applies to both singles and doubles.

At 20–20 (deuce), the game continues with each side trying to build a 2-point lead. This can extend the game well beyond 21 points — but the BWF introduced a hard cap at 30–29 to prevent marathon games: the first player or pair to reach 30 wins the game, regardless of margin. The 29–29 moment (called "setting") is particularly dramatic — the very next point determines the winner.

This validator takes the current score, games won, and who is serving to instantly tell you which court the server must stand in, whether the game is in deuce or setting, and what the ruling is on the next service. It's a useful courtside tool for umpires, coaches, and players settling disputed service positions.