Beach volleyball scoring system

Why is a set in beach volleyball (and also in badminton) won when the first team reaches 21 points and not with a nice and tidy score like 20 or 25? I know that table tennis had a similar system until some years ago, but why such an odd number?

Well has anyone any ideas?

Moved to the Game Room.

samclem, moderator

They score beach volleyball? I never noticed.

I don’t know if this answers the why but I notice that indoor volleyball sets used to play (and the deciding set still is played) to 15 which happens to be triangular number (1+2+3+4+5=15). 21 is the next triangular number in the series (1+2+3+4+5+6=21). Maybe triangular numbers seem more special?

21 is not an uncommon winning score for games. I believe it’s true for badminton and lots of backyard games (lawn golf, horshoes, washers, etc.).

As to the origin… /shrug.

Why is 21 any odder of a number than 25?

In its early days, baseball was won by the first team to score “21 aces” aces simply be4ing what we now call runs.

For beach volleyball, they switch sides on the court every 7 points. That works out to 21 right there.

It used to be to 15 points but you had to be the serving team to get the point. Those matches where teams kept switching serves without winning points (called sideout) took too long, so now it’s rally scoring where every serve always generates a point unless the ref calls for a replay of the point for some technical reason (like the ref blew the whistle accidentally and play stopped - ref’s fault, replay the point).

My sense is that 21 points turned out to generate the right length of play - not too long, not too short, and spectators enjoyed the games. Without the fans, there’d be no ticket sales, no sponsors, and eventually no game.

Yeah, I’ve been able to find where FIVB changed to rally scoring and a different court size in 2002, but not why they went to 21 points, while indoor had gone to 30 points.

But going along with what MenaceKiller wrote above, they switch sides during a set several times because wind and sun can cause one side of the court to be seriously advantageous. If you go to 25, that might be a switch every 5 serves, which seems too often. Go to 30 and you might divide it to every 10, and that’s probably too long to let one team have an advantage. You could do splits at 6 or 8 with a 24-point game, but that seems a stranger number than 21.