# What is the difference between First Ball Side Out (FBSO) and Side Out (SO)?

Nov 27, 2018 FAQ

That is a very good question and one we get a lot. For the following scenarios consider this setup.

Team A: Awesome Attacker / Big Blocker
Team B: Super Setter / Dark Digger

First Ball Side Out means you’re the receiving team and you’re killing the ball with your first attack. Let’s have a look at the following history.

No. Code Player Skill Type Evaluation Score
1 a2SM+ Dark Digger Service Jump Float Positive 0:0
2 *1RM+ Awesome Attacker Reception On Jump Float Positive
3 *2EH+ Big Blocker Setting High Ball Positive
4 *1AH# Awesome Attacker Attack High Ball Winning 1:0

In the table above Team B serves and Team A receives. Team A has exactly one Side Out and is able to kill the ball on their first attack.

Their First Ball Side Out (FBSO) is 100%.

$$\text{FBSO} = \frac{1\,\text{First Ball Kill}}{1\,\text{Service}} * 100 = 100\%$$

Their Side Out (SO) is also 100%.

$$\text{SO} = \frac{1\,\text{Point}}{1\,\text{Service}} * 100 = 100\%$$

Obviously it is a very simple example and the calculations are easy. So let’s create a bit more complex scenario. The first four moves are the same. Team B serves and Team A is able to kill the ball on their first attack.

No. Code Player Skill Type Evaluation Score
1 a2SM+ Dark Digger Service Jump Float Positive 0:0
2 *1RM+ Awesome Attacker Reception On Jump Float Positive
3 *2EH+ Big Blocker Setting High Ball Positive
4 *1AH# Awesome Attacker Attack High Ball Winning 1:0
5 *1SQ= Awesome Attacker Service Jump Error 1:1
6 a1SQ+ Super Setter Service Jump Positive
7 *2RQ/ Big Blocker Reception On Jump Poor
8 *1EH- Awesome Attacker Setting High Ball Poor
9 *2AM+ Big Blocker Attack Half Ball Positive
10 a1DM# Super Setter Dig On Half Ball Attack possible
11 a2EH# Dark Digger Setting High Ball Perfect
12 a1AH= Super Setter Attack High Ball Error 2:1

This time the First Ball Side Out (FBSO) percentage is 50%. The yellow line shows an attack that wasn’t a direct kill. Team B was able to dig the ball and start an attack.

$$\text{FBSO} = \frac{1\,\text{First Ball Kill}}{2\,\text{Serves}} * 100 = 50\%$$

The Side Out (SO) percentage is still 100%. Team B made an error on their attack after they were able to dig the ball. Thus Team B did not get the break and Team A was still able to hold the Side Out. Although it wasn’t in their own hands after their attack that wasn’t a kill. They dependent on Team B.

$$\text{SO} = \frac{2\,\text{Points}}{2\,\text{Serves}} * 100 = 100\%$$

## How does spolytics calculate the values?

First of all we generate the phase for every move. We have three different phases: Service, Reception and Transition. Next is adding the currently serving team to each move. The table from above would look like this.

No. Code Player Skill Type Evaluation Phase Serving Team Score
1 a2SM+ Dark Digger Service Jump Float Positive Service B 0:0
2 *1RM+ Awesome Attacker Reception On Jump Float Positive Reception B
3 *2EH+ Big Blocker Setting High Ball Positive Reception B
4 *1AH# Awesome Attacker Attack High Ball Winning Reception B 1:0
5 *1SQ= Awesome Attacker Service Jump Error Service A 1:1
6 a1SQ+ Super Setter Service Jump Positive Service B
7 *2RQ/ Big Blocker Reception On Jump Poor Reception B
8 *1EH- Awesome Attacker Setting High Ball Poor Reception B
9 *2AM+ Big Blocker Attack Half Ball Positive Reception B
10 a1DM# Super Setter Dig On Half Ball Attack possible Transition B
11 a2EH# Dark Digger Setting High Ball Perfect Transition B
12 a1AH= Super Setter Attack High Ball Error Transition B 2:1

From this combination of statically recorded and dynamically enhanced data we count the overall receptions from Team A and the kills during the Reception phase while Team B was serving. We devide the further by the latter and get the overall First Ball Side Out (FBSO) percentage.

As you might notice service errors from the opponent team are not included in the calculation. Since you didn’t do anything to get the point it does not count towards your First Ball Side Out (FBSO) percentage. However they are included in your Side Out (SO) percentage. As the formula said you won the point when the opponent team served. In the end it does not matter if you include service errors or not. You just have to do it consistently so you’re able to compare different FBSO from different matches and different teams.

## What does it mean for my team?

You should always strive for a high FBSO. The higher the harder it is to win against you. A high SO is great too but it shows some weaknesses on your first attack. It also demonstrates the inability of your opponent to score during transition. Not being able to get your Side Out makes your match play much harder. Your opponent will be able to get some chances to break which in return means that you must get some breaks as well to win the match.

If your First Ball Side Out (FBSO) is higher than your Side Out (SO) you’re doing something wrong. There might be an error in your data.