{
    "table_name": "raw_kaggle",
    "primary_key": "Name, Date, Tournament, Rd",
    "candidates": [
        {
            "rank": 0,
            "partition_key": "Name",
            "partition_key_label": "E",
            "partition_key_reasoning": "Name identifies the player whose match history is traced. It has 462 unique values, RPUV ~513, and top-3 coverage of only 1.74%. RPUV is above the ideal 2-100 range but coverage is well spread, and no other column organizes the table better.",
            "clustering_key": "Date",
            "clustering_key_label": "S",
            "clustering_key_reasoning": "Date is the match or tournament-start date, with 2698 unique values and RPUV ~88. It orders each player's matches over time. It is stored as text in d-Mon-yyyy format, so it needs parsing to sort correctly. Rd refines the order within a tournament, but it is a categorical round code.",
            "world_line": "Name",
            "session_column": "Tournament",
            "confidence": "MEDIUM",
            "notes": "Each row is one match from one player's perspective, so it is an event log per player. Rows are not sorted chronologically overall, and within a tournament the rounds run in descending order (F first). The composite primary key is Name + Date + Tournament + Rd. Tour Finals round-robin (RR) matches can repeat within a player-tournament-date, so uniqueness is not guaranteed without the 'against' column. Adding 'against' gives a safer key, since it has 0.977 uniqueness."
        },
        {
            "rank": 1,
            "partition_key": "Tournament",
            "partition_key_label": "E",
            "partition_key_reasoning": "Tournament has 3572 unique values (an edition-level name such as 'Aachen CH'), RPUV ~66, and top-3 coverage of 5.01%. It falls within the acceptable RPUV range and groups all matches from one tournament.",
            "clustering_key": "Date",
            "clustering_key_label": "S",
            "clustering_key_reasoning": "Date orders matches within a tournament. RPUV is ~88 overall, and text parsing is needed.",
            "world_line": "Tournament",
            "session_column": null,
            "confidence": "LOW",
            "notes": "This is an alternative perspective for tournament-centric analysis. The tournament is a context entity rather than the main actor, so it is less natural than partitioning by player."
        }
    ]
}