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What Position Does This Footballer Play?

From age, height and per-match statistics, does this player play as a goalkeeper, defender, midfielder or forward? Scouts use the same idea to find players who could switch roles.

Use caseMedia and gamesPredictionModel evaluation

The table

3,611 players with age, height and per-match performance statistics, labelled by position. It's in Welt's research catalogue as Football Player Position, 3,611 rows by 12 columns, licensed CC0. The catalogue measures its signal at 0.78. At 3,611 rows and 11 features, TabICLv2, Kumo Tabular Medium and Mitra-v2 take the table as it is. The others can't take a table this size, so the walkthrough leaves them out.

Walkthrough

  1. Load it from the catalogue

    Find the table, read its recorded target and print the column names.

    import pandas as pd
    from welt import Client
    
    with Client() as client:
        item = client.research_datasets(q="football player position", limit=1)["items"][0]
        info = client.research_dataset(item["id"])
        data = client.load_research_dataset(item["id"])
    
    target = info["targets"][0]
    target = target["name"] if isinstance(target, dict) else target
    print([column["name"] for column in info["schema"]], target)
  2. Pick the rows

    Set aside 20 rows to predict at the end, and keep the rest for the models to learn from.

    known = data.dropna(subset=[target])
    new_rows = known.sample(20, random_state=1)
    table = known.drop(new_rows.index)
  3. Compare the models and predict

    The models compete on the same folds against a simple guess, then the top-ranked one is fitted on the whole table. ROC AUC runs from 0.5, a coin toss, to 1, a perfect ranking, and a lower Brier score means the probabilities can be trusted more. The last table puts each prediction next to the real answer.

    with Client() as client:
        evaluation = client.evaluate(table, target, task="classification", seed=7,
                                     models=["tabicl-v2", "kumo-medium", "mitra-v2"])
        model = evaluation.fit()
    
    print(evaluation.summary()[["name", "rank", "roc_auc_mean", "brier_mean"]])
    features = new_rows.drop(columns=target)
    print(pd.DataFrame({"actual": new_rows[target].values, "predicted": model.predict(features),
                        "probability": model.predict_proba(features).max(axis=1)}))

What you get

A position per playerWith a probability for each role.
Players who fit two rolesLook for players split between positions.
A strong signalThe catalogue measures a high signal.

Try it

Use Open with to run the research datasets notebook in Colab, Kaggle or Jupyter and search for "football player position", or run the code above after pip install "welt-client[parquet]".