Theory / Training statistics
Performance
How much of the available table can you convert into successful shots before a miss?
Performance averages your normalized shot streaks across the video. Longer streaks raise the score, and a new rack lets a streak continue. Available balls give each segment its scale.
One visit, several segments
A visit runs until a miss or the end of the video. A segment is the part of that visit played with one setup of available balls. A new rack starts another segment, even though the visit continues.
01 · Start with 9
9 successful shots
9 / 9 = 1.000
02 · New rack, same visit
15 available · 5 successful
5 / 15 = 0.333…
03 · Miss ends the visit
Add both segments
1 + 0.333… = 1.333…
Visit score = sum of (successful shots / object balls at the start of each segment)
Performance = 1000 × sum of visit scores / number of visits
The example gives 1333 Performance if it is the only visit in the video. There is no 1000-point ceiling. Values are rounded only for the final displayed score.
What counts
- A miss ends the visit
- A miss on the first shot still counts as a visit, with a score of zero. The next regular shot starts a new visit.
- A new rack continues the visit
- Start a new segment and add its fraction to the same visit. Break shots do not count as successes or misses in this calculation.
- Count successful shots
- One successful shot counts once, even if it pockets several balls. Pocket choice does not affect the score.
- Exclude the cue ball
- Use the object balls available before the first regular shot of the visit, and again before the first regular shot after a new rack.
- The video ends the final visit
- An unfinished visit is included when the recording ends. A final miss does not create an extra empty visit.
- Single-player practice
- This calculation is for individual practice. Videos identified as having multiple players do not receive this score.
The denominator stays fixed within each segment. It does not shrink as you pocket balls. After a miss, the next visit gets a fresh denominator from the balls then available.
For example, if a table begins with 10 visible balls including the cue ball, the denominator is 9. If a later visit starts with 5 visible balls including the cue ball, its denominator is 4.
Available-ball counts come from the first observed frame of each shot. A break marks a new segment; an increase in the observed ball count also indicates a new setup. Missing counts prevent a reliable score, and detection errors can affect the result.
From a visit to a video
| Visit | Calculation | Performance |
|---|---|---|
| 9 successes from 9 available | 9 / 9 | 1000 |
| 15 successes from 15 available | 15 / 15 | 1000 |
| 9 from 9, then 15 from a new 15-ball setup | 9 / 9 + 15 / 15 | 2000 |
| 9 from 9, then miss immediately after a new rack | 9 / 9 + 0 / 15 | 1000 |
| Miss the first shot | 0 / available balls | 0 |
A whole video: three visits score 1.0, 0.5 and 0. The final Performance is 1000 × (1 + 0.5 + 0) / 3 = 500. Every visit has equal weight, including a first-shot miss.
Starting a new rack never removes the score already earned within the visit. It opens another segment whose successful shots add to that score.
When a result is unknown
An unknown regular shot can either continue the visit as a success or end it as a miss. We calculate the lowest and highest possible video scores across those outcomes, then display the midpoint.
5 object balls at the start → success → success → unknown → end of video
If the unknown shot missed
2 / 5 × 1000 = 400
If the unknown shot succeeded
3 / 5 × 1000 = 600
Displayed Performance: (400 + 600) / 2 = 500
With several unknown shots, all possible combinations are accounted for: a miss can change both the number of visits and their starting ball counts. The displayed value is the midpoint of the possible range, not a probability-weighted prediction.
Editing a shot result recalculates the training score. Once every result is known, the lower and upper bounds coincide.
Explore the calculation
Change the available balls and successful shots below. Add a new rack to the same visit, or add visits that ended with an immediate miss.
Visit score: 9/9 + 5/15 = 1.333
Video score: 1000 × 1.333 / 1 visit
1333 Performance
This example ends the main visit with a miss or the end of the video. Each successful shot counts once. The cue ball is excluded from the available-ball counts.
How to read your score
1000 means an average visit score of 1. This can come from one complete segment or fractions accumulated across several setups. It does not mean 100% accuracy, and it is not a universal skill grade.
Normalizing by available balls makes 9 successful shots from 9 and 15 from 15 equivalent. It also makes one successful shot from one available ball worth a full segment. The score describes conversion relative to the starting opportunity, rather than raw streak length.
Because successes are counted as shots, pocketing several balls at once does not add several successes. A cleared table can therefore contribute less than 1. Balls pocketed on the break are excluded; the next segment uses the balls available after the break.
Rules, shot difficulty, detection quality and where a recording starts or stops still influence the result. Two videos with the same Performance can contain very different streak lengths. Read the score alongside accuracy, shot count and the actual shot sequence.