{
    "classifications": [
        {
            "column": "Name",
            "label": "none",
            "confidence": 0.6,
            "reason": "Player name repeats across many matches; 462 distinct of 237k rows, a descriptive attribute rather than a join key"
        },
        {
            "column": "Date",
            "label": "none",
            "confidence": 0.9,
            "reason": "Match date, low cardinality with heavy repetition"
        },
        {
            "column": "Tournment",
            "label": "none",
            "confidence": 0.6,
            "reason": "Tournament name/edition label repeats; descriptive attribute"
        },
        {
            "column": "Surface",
            "label": "none",
            "confidence": 0.95,
            "reason": "Low-cardinality categorical"
        },
        {
            "column": "Rd",
            "label": "none",
            "confidence": 0.95,
            "reason": "Round code, categorical"
        },
        {
            "column": "Rk",
            "label": "none",
            "confidence": 0.9,
            "reason": "Player ranking measure, not a key"
        },
        {
            "column": "vRk",
            "label": "none",
            "confidence": 0.9,
            "reason": "Opponent ranking measure"
        },
        {
            "column": "against",
            "label": "none",
            "confidence": 0.7,
            "reason": "About 97.7% distinct (231760 of 237185), below the 98% near-key threshold; messy opponent text"
        },
        {
            "column": "Score",
            "label": "none",
            "confidence": 0.9,
            "reason": "Match score text, repeats"
        },
        {
            "column": "Dr",
            "label": "none",
            "confidence": 0.95,
            "reason": "Statistic stored as text"
        },
        {
            "column": "A%",
            "label": "none",
            "confidence": 0.95,
            "reason": "Percentage statistic"
        },
        {
            "column": "Df%",
            "label": "none",
            "confidence": 0.95,
            "reason": "Percentage statistic"
        },
        {
            "column": "1stIn",
            "label": "none",
            "confidence": 0.95,
            "reason": "Percentage statistic"
        },
        {
            "column": "1st%",
            "label": "none",
            "confidence": 0.95,
            "reason": "Percentage statistic"
        },
        {
            "column": "2nd%",
            "label": "none",
            "confidence": 0.95,
            "reason": "Percentage statistic"
        },
        {
            "column": "Bpsvd",
            "label": "none",
            "confidence": 0.95,
            "reason": "Break points saved ratio, measure"
        },
        {
            "column": "Time",
            "label": "none",
            "confidence": 0.95,
            "reason": "Match duration, measure"
        }
    ]
}