A sport event defined by the Unified Odds Feed is a match, race and/or outright. Every message contains information about only one sport event. For example, an odds change message typically includes all changes to any markets for a particular sport event. All sport events have a unique ID that identifies the sport event in the messages. The API then provides endpoints that enable you to look up fixture information for a given sport event ID (https://iodocs.betradar.com). More information about sport events in context can be found HERE.
<odds_change product="1" event_id="sr:match:14011583" timestamp="1522772129383">
<sport_event_status status="0" match_status="0"/>
<odds>
.... Info about markets....
</odds>
</odds_change>