RBI, or Run Batted In, is a statistic in baseball that measures a player's effectiveness in driving in runs. When a player hits the ball and a runner scores as a result, the player is credited with an RBI. This statistic helps evaluate a player's ability to contribute to their team's scoring. An RBI can occur in various ways, such as through a hit, a sacrifice fly, or a walk with the bases loaded. It is an important metric for assessing a player's offensive performance and is often used alongside other statistics like batting average and home runs.