> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplift.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Time to Contact

> Duration from the start of the serve to ball contact.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** seconds (s)
* **Column Name:** `time_to_contact`
* **Measurement:** Duration from [Initiation](/biomechanics/activities/tennis/events/initiation) to [Apex](/biomechanics/activities/tennis/events/apex) (ball contact)

## Description

Time to contact measures how long the serve takes from its initial movement to ball contact. Shorter times generally reflect a quicker, more compact motion, while longer times can reflect a more deliberate rhythm or timing inefficiencies.

## Use Cases

* Serve tempo and rhythm analysis
* Timing consistency across trials
* Comparison across players