How Badminton works

Matches are best of three games to 21 points, using rally scoring — a point is won on every rally regardless of who served. A game must be won by two, and if the score reaches 29–29 the next point decides it.

• 21 points wins a game, but by a margin of two
• At 29–29, the first to 30 wins outright
• Every rally scores, for either side
• Players change ends after each game, and at 11 in the deciding game

The serve must be struck underarm with the whole shuttle below 1.15 m at the moment of contact, and travel diagonally into the opposite service court. That height restriction is why the serve is a defensive shot in badminton, the opposite of tennis — a high serve invites an immediate smash.

• Contact must be below 1.15 m from the surface
• The racket head must point downwards on contact
• Serve from the right court on even scores, left on odd
• In doubles, only the serving side's scorer changes court

A feathered shuttle uses sixteen goose or duck feathers set in a cork base and decelerates violently after being struck — the highest recorded smash leaves the racket at over 480 km/h but arrives far slower. That deceleration is the whole reason the sport's tactics work: power alone cannot win a rally.

The court is 13.4 m long and 6.1 m wide for doubles, narrowed to 5.18 m for singles. The service court boundaries differ too: singles service is long and narrow, doubles service short and wide, which is why the tramlines matter differently depending on the format and the moment.

• Net height 1.55 m at the posts, 1.524 m at centre
• Singles uses the long, narrow court
• Doubles uses the full width but a shorter service box

A rally ends immediately on a fault, and the point goes to the other side. The rules on contact are unusually strict — touching the net at all, at any point in the rally, ends it.

• The shuttle lands outside the court, or fails to cross the net
• A player touches the net or its posts with racket, body or clothing
• The shuttle is hit twice, or carried on the racket face
• A player invades the opponent's court under the net

The rally is a constant negotiation between height and speed. Clears push opponents to the back, drops pull them forward, and the smash finishes the point — but only from a position where the opponent has been moved out of shape first. Deception, disguising a drop as a smash until the last instant, is what separates the elite.

• Clear — high and deep to the rear court
• Drop — landing just over the net
• Smash — steep and flat, the primary winning shot
• Net shot and lift — the close-range exchange