#separator:tab #html:false #tags column:4 Players on defense 9 on the field sports-baseball-rules-terms Innings in a standard baseball game 9 sports-baseball-rules-terms Outs per half-inning 3 sports-baseball-rules-terms Strikes for a strikeout 3 sports-baseball-rules-terms Balls for a walk 4 sports-baseball-rules-terms Pitcher The player who throws the ball to the batter sports-baseball-rules-terms Catcher The player who crouches behind home plate and catches pitches sports-baseball-rules-terms First baseman Defender who covers first base sports-baseball-rules-terms Second baseman Defender between first and second base sports-baseball-rules-terms Shortstop Defender between second and third base sports-baseball-rules-terms Third baseman Defender who covers third base sports-baseball-rules-terms Left fielder Outfielder on the left side sports-baseball-rules-terms Center fielder Outfielder in the middle sports-baseball-rules-terms Right fielder Outfielder on the right side sports-baseball-rules-terms Designated hitter A player who bats in place of the pitcher sports-baseball-rules-terms Home plate The base where batters stand and runners score sports-baseball-rules-terms Bases Four spots a runner must touch in order: first, second, third, home sports-baseball-rules-terms Diamond The infield shape formed by the bases sports-baseball-rules-terms Base paths The lines between bases sports-baseball-rules-terms Distance between bases (MLB) 90 feet sports-baseball-rules-terms Pitching distance (MLB) 60 feet 6 inches sports-baseball-rules-terms Pitcher's mound The raised area where the pitcher stands sports-baseball-rules-terms Strike zone The area over home plate between knees and chest where a pitch counts as a strike sports-baseball-rules-terms Strike A pitch in the strike zone, a swing and miss, or a foul with fewer than two strikes sports-baseball-rules-terms Ball A pitch outside the strike zone that the batter doesn't swing at sports-baseball-rules-terms Foul ball A batted ball landing outside the foul lines sports-baseball-rules-terms Fair ball A batted ball in play inside the foul lines sports-baseball-rules-terms Single A hit that gets the batter to first base sports-baseball-rules-terms Double A hit that gets the batter to second base sports-baseball-rules-terms Triple A hit that gets the batter to third base sports-baseball-rules-terms Home run A hit that lets the batter circle all the bases and score sports-baseball-rules-terms Grand slam A home run with the bases loaded, scoring 4 runs sports-baseball-rules-terms RBI Run batted in sports-baseball-rules-terms Run A point scored when a runner touches home plate sports-baseball-rules-terms Bunt Tapping the ball softly without a full swing sports-baseball-rules-terms Sacrifice fly A fly ball caught for an out that lets a runner score sports-baseball-rules-terms Stolen base A runner advances while the pitcher throws sports-baseball-rules-terms Force out A runner must move to the next base and is tagged out there sports-baseball-rules-terms Tag out A fielder touches the runner with the ball sports-baseball-rules-terms Fly out A batted ball caught in the air sports-baseball-rules-terms Ground out A grounder fielded and thrown to first for an out sports-baseball-rules-terms Double play Two outs on one play sports-baseball-rules-terms Triple play Three outs on one play sports-baseball-rules-terms Strikeout Three strikes by a batter sports-baseball-rules-terms Walk (base on balls) Four balls and the batter takes first base sports-baseball-rules-terms Hit by pitch A batter hit by a pitch goes to first base sports-baseball-rules-terms Error A fielding mistake that lets a runner reach base or advance sports-baseball-rules-terms Infield fly rule An easily caught fly ball with runners on makes the batter out sports-baseball-rules-terms Balk An illegal move by the pitcher with runners on base sports-baseball-rules-terms Pitch types Fastball, curveball, slider, changeup sports-baseball-rules-terms Fastball A pitch thrown with top speed sports-baseball-rules-terms Curveball A pitch that curves as it nears the plate sports-baseball-rules-terms Changeup A slower pitch that looks like a fastball sports-baseball-rules-terms No-hitter A game in which one team gets no hits sports-baseball-rules-terms Perfect game No batter of the other team reaches base sports-baseball-rules-terms Batting average Hits divided by at-bats sports-baseball-rules-terms ERA Earned run average, a pitcher's average runs allowed per nine innings sports-baseball-rules-terms Bullpen Where relief pitchers warm up sports-baseball-rules-terms Dugout The bench area for players sports-baseball-rules-terms Batter's box The area where batters stand beside home plate sports-baseball-rules-terms On-deck circle Where the next batter waits sports-baseball-rules-terms Seventh-inning stretch A tradition where fans stand and sing Take Me Out to the Ball Game sports-baseball-rules-terms Umpire The official who calls balls, strikes and outs sports-baseball-rules-terms Softball pitching style Underhand (windmill) sports-baseball-rules-terms Little League Youth baseball program founded in 1939 sports-baseball-rules-terms MLB Major League Baseball sports-baseball-rules-terms World Series The championship series of MLB sports-baseball-rules-terms Jackie Robinson Broke baseball's color barrier in 1947 sports-baseball-rules-terms Babe Ruth Famous slugger who hit 714 career home runs sports-baseball-rules-terms Hank Aaron Hit 755 career home runs sports-baseball-rules-terms