In volleyball, attackers use two-digit numbers to let their setter know where to set the ball. These numbers refer to two things: the section of the net, and the tempo of the ball. Tempo is the speed/trajectory at which the ball is set. The picture above shows 4 different tempos to the 1 section:
A 1 tempo ball is very fast and has no arc. You should already be in the air before the ball leaves the setter’s hands to successfully attack a 1 tempo ball. The setter needs to see where you are and shoot the ball to where you would be contacting it. 1 tempo sets are commonly run in the 5 section (a 51, commonly called a “1-ball“) and 7 section (a 71, commonly called a “Back 1“) of the net. Sometimes 1 tempo balls are run to the 1 section of the net (commonly called a “Fast Shoot“), but it requires a skilled setter to execute them consistently.
A 2 tempo ball is fast but has a little arc to it. You should be on the second step of your 4 step approach when the ball leaves the setter’s hands. 2 tempo sets are commonly run in the 1 section of the net (a 12, commonly called a “Slow Shoot”) and, at beginner level, to the 5 section of the net (a 52, commonly called a “2-ball“).
A 3 tempo ball is a slower set and has arc. A 3 tempo gives the attacker enough time to evaluate exactly where to take-off from mid approach. 3 tempo sets are commonly run in the 9 section of the net (a 93, commonly called a “Back 3” or “Red”).
A 4 tempo ball is the slowest set and is all arc. A 4 tempo gives the hitter plenty of time to evaluate the block, the defense, and where to take-off from when approaching. They’re mainly kept a meter off the net to give the attacker plenty of field-of-attack to work with. 4 tempo sets are basically only run in the 1 section of the net (a 14, commonly called a “4-ball“).
Can I run X tempo in Y section of the net?
I mean, sure. Let’s take a look at the 8 section of the net:
Here are 4 different sets. Of the four, 81, 82, and 83 are all commonly run sets, with 84 being the least commonly run — 4 tempo is generally just too high a set for weak side.
Anyway, you can run any tempo to any section of the net. You can even run 5 tempo balls (a “ceiling” ball) to the 10 section (outside the antenna) if you’d like. The tempo and sections are just a guideline that volleyball players follow so that when playing with new people, everyone has a common language/understanding of attacking setups.
However, it should be noted that a lot of section/tempo combinations aren’t commonly used for attacks. For example, like I mentioned above with the 84, it’s not likely that you’ll see a 64, or a 44, as it gives a ton of time to the opponent’s middle blocker to prepare a good block, and with a good block comes less field-of-attack to work with. If you’re looking for a list of the most common sets in volleyball, I’ve compiled that here.
A Final Note on Tempo
Conceptually, think of tempo as the amount of time you give the defense to prepare. The slower the tempo, the more time the defense has to set up to block (or dig) your attack. Generally, when attacking 3/4 tempo balls, your take-off approach will be a meter or so off the net, so you have enough space (field-of-attack) to work with, because it’s likely you’ll be hitting around a block and looking for a hole in the defense.