first base without risk of being put out, called a base on balls or a walk (abbreviated BB). If a pitch touches the batter (or the batter's clothes), the umpire declares a hit by pitch (abbreviated HBP) and the batter is awarded first base, unless the umpire determines that the ball was in the strike zone when it hit the batter, or that the batter did not attempt to avoid being hit. In practice, neither exception is ever called unless the batter obviously tries to get hit by the pitch; even standing still in the box will virtually always be overlooked, and the batter awarded first. In addition, if the batter swings at a pitch that hits him, it counts as a strike. If the catcher's mitt, catcher's mask, or any part of the catcher comes in contact with the batter and/or the batter's bat as the batter is attempting to hit a pitch, the batter is awarded first base, ruled "catcher's interference". Baserunning Once a batter becomes a runner and reaches first base safely, he is said to be "on" that base until he attempts to advance to the next base, until he is put out, or until the half-inning ends. In order to be safe a runner must beat the ball to the bag. When two or more runners are on the basepaths, the runner farther along is called a lead runner or a preceding runner; any other runner is called a trailing runner or a following runner. Runners on second or third base are considered to be in scoring position since ordinary hits, even singles, will often allow them to score. A runner legally touching a base is "safe"—in most situations he may not be put out. Runners may attempt to advance from base to base at any time (except when the ball is dead). A runner that must attempt to advance is forced , when all previous bases are occupied and a batted ball that touches the ground is a fair ball. The runner forced to advance toward the next base is considered "forced out" if a fielder holding the baseball touches the intended base before the baserunner arrives. When a batted ball is hit in the air, i.e., a fly ball, and caught by the defending team, runners must return and "retouch" the base they occupied at the time of the pitch. The common name