Official Rules of Major League Baseball

9.12 Errors

9.12 Errors An error is a statistic charged against a fielder whose action has assisted the team on offense, as set forth in this Rule 9.12 (Rule 10.12). (a) The official scorer shall charge an error against any fielder: (1) whose misplay (fumble, muff or wild throw) prolongs the time at bat of a batter, […]