Entity resolution is the quiet hard problem of sports data: books name teams differently, double-headers share a date, and postponed games move. A stable event ID absorbs all of that - store it as your primary key at bet time, and later joins against closing lines, scores, or other books' prices become trivial instead of fuzzy string matching.
Every odds payload carries the event's ID plus commence time and team names; per-event endpoints and the 1.7M+ closing-line historical archive key on the same identifier, which is what makes bet-time-to-close CLV joins a one-liner.