An indoor volleyball match is played as a best-of-five series of sets. The first four sets, if needed, are each played to 25 points; if the match reaches a fifth and deciding set, that set is shortened to 15 points. In every case, a set cannot be won by a single point at the target score — a team must lead by at least two points, so a set that reaches 24-24 (or 14-14 in the fifth) continues until one side pulls two points ahead, however long that takes.
Beach volleyball follows the same two-point-margin principle on a shorter scale: a match is best-of-three sets, the first two played to 21 points and, if a third set is needed, that decider is played to 15. Teams switch sides of the court periodically during long sets in both disciplines — every seven points in a set to 21 or 25, and every five points in a deciding set — mainly to offset the effect of wind, lighting or a slanted indoor sun through windows on either side.
Why a deciding set is shorter
Shortening the final set to 15 points (or 15 in beach as well) keeps a match from running excessively long once it has already gone the distance, while the two-point-margin rule is preserved so the deciding set still has to be won outright on merit rather than by a single lucky point.
Sweeps, deciders and how coaches think about format
Because a five-set indoor match can be won in as few as three straight sets (a sweep) or stretch to a full deciding fifth set, coaches manage player rotations, timeouts and substitution budgets with total match length in mind, not just the current set. A team that wins the first two sets comfortably may rest a key player in a low-stakes third set, for example, while a match that reaches a tense fifth set forces every remaining substitution and timeout to be spent with unusually high stakes attached, since there is no sixth set left to fall back on if the decision proves wrong.
