Ratings Refresh refers to a series of player base card updates in FIFA Ultimate Team in which the updated cards contain upgraded or downgraded stats and a new Overall Rating (OVR). The updates which could be either an upgrade or a downgrade, are based on the performance that their real life players have shown on the filed during the past half season.
Previously known as Winter Upgrades & Downgrades, EA Sports named this update event as "Ratings Refresh" for the first time in FIFA 17. Ratings Refresh event happens during the football winter break every year (from mid-December to late February). EA releases the list Ratings Refresh for each country league just before the updated player items are coming to FIFA Ultimate Team.