Second-phase corner sequences

wa_setpieces.core.phases classifies what happens after a corner is delivered: was it cleared immediately, did it produce a direct shot, or did the ball stay alive for a second-phase shot (a knockdown, blocked clearance, or loose ball the attacking team won again before the danger was cleared).

Note the defending team’s events are recorded in their own attacking direction, so we mirror them onto the attacking team’s frame with wa_setpieces.to_reference_frame() before plotting anything – see that function’s docstring for how this was verified against the data.

from pathlib import Path

from wa_setpieces import load_matches
from wa_setpieces.core.phases import second_phases
from wa_setpieces.viz.plots import plot_second_phase

try:
    _here = Path(__file__).resolve().parent
except NameError:
    _here = Path.cwd()
DATA = _here.parent / "tests" / "data" / "sample_match.json"

events = load_matches(DATA)

Classify every corner in the match:

corners = second_phases(events, "corner")
corners[["delivery_event_id", "cleared_immediately", "second_phase_shot", "phase_events_n"]]

	delivery_event_id	cleared_immediately	second_phase_shot	phase_events_n
0	191	False	False	11
1	223	False	False	5
2	404	False	False	11
3	482	False	False	6
4	610	False	True	5
5	613	False	False	8
6	723	False	False	9
7	730	False	True	9
8	786	False	False	1

Plot the sequence for the first corner that produced a second-phase shot. Numbered grey dots are the contested touches after the delivery; the gold dot is the shot that eventually resulted.

shot_corners = corners.loc[corners["second_phase_shot"], "delivery_event_id"]
fig, ax = plot_second_phase(events, int(shot_corners.iloc[0]))

And one that was cleared immediately, for contrast:

cleared = corners.loc[corners["cleared_immediately"], "delivery_event_id"]
if not cleared.empty:
    fig, ax = plot_second_phase(events, int(cleared.iloc[0]))