wa-setpieces 0.4.0

Set-piece metrics and mplsoccer pitch visualizations (penalties, kick-offs, free kicks, corners, throw-ins, goal kicks) from Opta F24 event data, including second phases, xT, zones and retention

wa-setpieces

Set-piece metrics for football (soccer) matches from Opta / Stats Perform F24 event-feed JSON exports: penalties, kick-offs, free kicks, corners, throw-ins and goal kicks.

Given a raw F24 match file, this package tags every set-piece restart, aggregates attempts/success rates by team and player, tracks pass end locations for delivery maps, and links each set piece to the shot or goal it produced (via Opta's assist-chain qualifier). It also covers, for corners and free kicks specifically: second-phase detection, Expected Threat (xT), pitch zones/thirds/channels, and possession retention — with pitch plots built on mplsoccer.

Full documentation, with a runnable plot gallery: https://waltzinganalytics.readthedocs.io

Install

pip install wa-setpieces

Not yet published to PyPI? Install from source instead:

git clone https://github.com/marclamberts/waltzinganalytics.git
cd waltzinganalytics
pip install -e .

Quickstart

from wa_setpieces import load_events, set_piece_summary

match = load_events("match.json")
summary = set_piece_summary(match.events)
print(summary)

              contestantId set_piece_type  attempts  successful  success_rate  shots  goals
cxb4hqite921i...      corner         2           1         0.500      1      0
cxb4hqite921i...   free_kick        12           9         0.750      0      0
cxb4hqite921i...   goal_kick         8           5         0.625      0      0
cxb4hqite921i...    kick_off         1           1         1.000      0      0
cxb4hqite921i...    throw_in        20          16         0.800      1      0
...

Second phases, xT, zones and retention

from wa_setpieces import (
    second_phases, second_phase_summary,   # corner/free-kick second-phase shots
    retention_detail, retention_rate,      # possession retained N seconds later
    add_thirds, add_channels, add_zone_grid,  # pitch location tagging
    XTModel, set_piece_delivery_xt, set_piece_xt_summary,  # Expected Threat
)

second_phases(match.events, "corner")           # per-corner: cleared / first-phase shot / second-phase shot
second_phase_summary(match.events, "free_kick") # per-team roll-up

retention_rate(match.events, "corner")          # per-team: % of corners where the ball is retained ~8s later

tagged = add_thirds(match.events)               # defensive_third / middle_third / attacking_third
tagged = add_channels(tagged, n=5)              # wide / half-space / central

model = XTModel.fit(match.events)               # fit an xT grid (fit on many matches for real use!)
set_piece_xt_summary(match.events, "corner", model)  # total/average xT added per team

All four are derived heuristics, not raw Opta fields — see docs/source/advanced.rst (or the hosted docs) for the exact assumptions and tunable thresholds behind each one.

Plots

pip install -e ".[viz]"   # matplotlib + mplsoccer

from wa_setpieces.viz import (
    plot_delivery_map,      # arrow map of deliveries, colored by outcome
    plot_zone_heatmap,      # where events happen, gridded onto the pitch
    plot_xt_grid,           # a fitted XTModel's grid, as a heatmap
    plot_second_phase,      # one corner/free-kick's phase sequence, numbered
    plot_team_comparison,   # grouped bars: both teams, every set-piece type
    plot_xt_added_bars,     # diverging bar chart of xT added per delivery
    plot_corner_sonar,      # polar plot of delivery angle + distance
    plot_match_timeline,    # every set piece on one shared match-minute axis
    plot_dashboard,         # one-figure report card combining several of the above
)

plot_delivery_map(delivery_locations(match.events, "corner"), title="Corner deliveries")
plot_dashboard(match.events, team_id, set_piece_type="corner")  # the "hero" figure

Every plotting function returns (fig, ax) (plot_dashboard returns just fig, being multi-panel) for further customization. Colors are assigned by the job they do — a validated categorical palette for team identity, a status pair for success/fail, single-hue sequential ramps for magnitude, and a diverging pair for signed quantities like xT added — not picked for looks; see wa_setpieces/theme.py. See the gallery for all nine plots with full source code.

Command line

wa-setpieces match.json
wa-setpieces match.json --csv summary.csv
wa-setpieces match.json --xt   # also fit + print xT for this match (illustrative on one match)

What counts as a set piece

Type	Detected on	Opta qualifierId
Penalty	shot event (miss/post/saved/goal)	9
Kick-off	pass event	279
Free kick	pass event (corners excluded)	5
Corner	pass event	6
Throw-in	pass event	107
Goal kick	pass event	124

These qualifier IDs are the standard Opta/Stats Perform F24 vocabulary and were cross-checked against a real match export (see tests/data/sample_match.json and tests/test_filters.py): tagged events line up with their expected pitch location (corner arc, touchline, centre spot, six-yard line).

Package layout

• wa_setpieces.loader — parse F24 JSON into a tidy pandas.DataFrame; load_events_multi stacks a whole season.
• wa_setpieces.constants — Opta typeId / qualifierId reference.
• wa_setpieces.filters — extract/tag each set-piece type.
• wa_setpieces.metrics — team/player counts, success rates, delivery locations.
• wa_setpieces.chains — link set pieces to the shots/goals they produced.
• wa_setpieces.zones — pitch thirds, channels and a configurable zone grid.
• wa_setpieces.phases — second-phase detection for corners/free kicks.
• wa_setpieces.retention — possession retention after any restart.
• wa_setpieces.xt — grid-based Expected Threat (xT), fit from data.
• wa_setpieces.viz — mplsoccer/matplotlib plots: delivery maps, heatmaps, sonar, timeline, dashboard (optional viz extra).
• wa_setpieces.theme — the validated color palette every plot draws from.
• wa_setpieces.cli — wa-setpieces command-line tool.

Development

pip install -e ".[dev]"
pytest

Releasing

Publishing to PyPI is automated via GitHub Actions trusted publishing (.github/workflows/publish.yml) — no API token stored anywhere. One-time setup (only a PyPI project owner can do this, since it requires logging into PyPI):

1. On PyPI: https://pypi.org/manage/account/publishing/ → add a pending trusted publisher with project name wa-setpieces, owner marclamberts, repository waltzinganalytics, workflow publish.yml, environment pypi.
2. From then on, publishing a GitHub Release (or pushing a v* tag) builds the sdist/wheel and uploads them automatically.

Docs

Docs are built with Sphinx (pydata-sphinx-theme + sphinx-gallery, the same stack mplsoccer's docs use) and hosted on Read the Docs (.readthedocs.yaml at the repo root). The gallery under examples_gallery/ is executed at build time, so its plots and DataFrame outputs are always current. To build locally:

pip install -e ".[docs]"
sphinx-build -b html docs/source docs/_build/html

License

MIT