How does 15-point (3x15) scoring work?

Q: How does 15-point (3x15) scoring work?

These are the BWF Laws that take effect on 4 January 2027 (Law 7): A match is the best of three games, unless otherwise arranged. Every rally scores a point, whoever served. A game is won by the first side to 15 points. At 14-all, the side that first gains a two-point lead wins the game. At 20-all, the side that scores the 21st point wins the game. The winner of a game serves first in the next game. So the longest possible game finishes 21-20. Intervals and changes of ends come at 8 points instead of 11.

Question

Accepted Answer

These are the BWF Laws that take effect on 4 January 2027 (Law 7):

A match is the best of three games, unless otherwise arranged.
Every rally scores a point, whoever served.
A game is won by the first side to 15 points.
At 14-all, the side that first gains a two-point lead wins the game.
At 20-all, the side that scores the 21st point wins the game.
The winner of a game serves first in the next game.

So the longest possible game finishes 21-20. Intervals and changes of ends come at 8 points instead of 11.