> ## 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.

# P7 Impact

> The moment of ball contact, the 'moment of truth' that determines where the ball goes. Also exposed under the legacy column name Ball Contact.

## Technical Details

* **Variable Type:** Event
* **Data Type:** Integer
* **Units:** Frame number
* **Column Name:** `p7_impact_frame`
* **Required for QA:** False
* **Measurement:** Minimum distance between the lead wrist and lead hip, searched between Top of Swing and Finish
* **Timing:** Between P6 Pre-Impact and P8 Release
* **Legacy Name:** Ball Contact

## Description

P7 Impact approximates the instant the club strikes the ball, identified as the frame where the lead wrist is closest to the lead hip. It is the primary reference event for Downswing Duration, Follow-Through Max X-Factor, and the angle-at-impact metrics.

## Use Cases

* Downswing Duration calculation
* Follow-Through Max X-Factor window start
* Angle-at-impact metrics