Ball Phase

A continuous span describing whether the ball is in play, out of bounds, or in a stoppage. Carries a phase enum: in_play, out_of_bounds, in_bounds_stoppage, half_kickoff.

Category: Structure

Properties

Property	Type	Description	Values
phase	str	Ball-phase span label.	in_play, out_of_bounds, in_bounds_stoppage, half_kickoff

Property Values

phase

A continuous span describing whether the ball is in play, out of bounds, or in a stoppage. Carries a phase enum: in_play, out_of_bounds, in_bounds_stoppage, half_kickoff.

Value	Description
in_play	Active gameplay. The ball is in bounds and the referee has not stopped play.
out_of_bounds	Between the ball crossing a touchline or goal-line and the restart.
in_bounds_stoppage	Play is paused but the ball is still on-pitch (e.g. foul, injury). Distinct from out_of_bounds.
half_kickoff	Single-frame kickoff anchor at the start of a period.

Accuracy

Engine output scored against ground truth on held-out evaluation games, metric frame_macro_f1 (per-frame, macro-averaged over classes), measured 2026-10-18; per-match confidence is the separate confidence_event property.

Ground-truth source	Accuracy	Macro F1	Frames
World Cup Broadcast	0.92	0.84	466,231
Senior broadcast pool	0.93	0.72	608,382
Non-broadcast youth pool	0.90	0.71	733,307
Senior tactical-camera pool	0.88	0.74	709,008

Querying

Request body for Query Intervals.

{
  "filters": [
    {
      "type": "event_property",
      "event_type": "ball_phase",
      "properties": []
    }
  ]
}

properties constrains the metadata fields listed above. See Event Property Filter.

Response

Shape of this event type in the Events endpoint response.

{
  "event_id": "06a0765b-0005-7005-8000-000000000005",
  "start": 125.5,
  "end": 135.5,
  "label": "in_play",
  "event_type": "ball_phase",
  "team_id": null,
  "timeline_confidence": null
}

label is the phase value, e.g. "in_play" or "out_of_bounds".