The infield shift in baseball is a defensive realignment from the standard positions, to place more fielders on one side of the field or another. Used primarily against left-handed batters, it is designed to protect against base hits pulled hard into the gaps between the fielders on one side. Originally called the Williams shift, it has periodically been referred to as the Boudreau shift or Ortiz shift since then. After shifts became very effective in reducing base hits by Major League Baseball (MLB) batters, MLB and the Major League Baseball Players Association (MLBPA) agreed to begin restricting shifts starting in the 2023 season.