{
    "classifications": [
        {
            "column": "name",
            "label": "none",
            "confidence": 0.6,
            "reason": "Player name repeats across rows (462 distinct of 6422); it is a descriptive attribute and is not a clear reference to another table's key."
        },
        {
            "column": "year",
            "label": "none",
            "confidence": 0.9,
            "reason": "Calendar year with 23 distinct values; a temporal attribute, not a key."
        },
        {
            "column": "tournament",
            "label": "none",
            "confidence": 0.6,
            "reason": "Tournament name repeats (370 distinct); a descriptive categorical attribute, not an ID reference."
        },
        {
            "column": "rounds",
            "label": "none",
            "confidence": 0.9,
            "reason": "A list-like string of rounds reached, with 159 distinct values; a descriptive attribute, not a key."
        }
    ]
}