Baseball: The rules for the casual viewer

Raymond Chen

Today is Independence Day, the national holiday of the United States, a holiday in which aliens blow up the world’s major cities. Baseball is known as the national pastime of the United States, so I’ll continue my “the minimum you need to know about a sport in order to watch a match and not be completely confused” series by taking on baseball.

Again, we assume that the equipment conforms to regulations, and that the players generally follow the rules.

Set-up: Each team consists of nine players. The officials are known as umpires.

  • One team is batting and the other is fielding.
  • The playing field is shaped roughly like a quarter-circle. A ball hit into the field is a fair ball; otherwise it is a foul ball.
  • Most of the action is concentrated in a square area (the diamond). At each corner is a base. Home plate (which is a base, even though its name is “plate”) is the vertex of the quarter-circle; the other bases are numbered counter-clockwise.
  • A player on the batting team scores a run by touching all the bases in sequence, ending at home plate.
  • When three players from the batting team have been put out, the fielding team comes to bat, and the batting team takes the field.
  • An inning is completed when each team has had a turn at bat and a turn in the field.
  • After nine innings, the team with more runs is the winner. If the game is tied after nine innings, extra innings are played until an inning completes with the score not tied.

Batting: A player from the fielding team (the pitcher) throws a ball toward a teammate (the catcher) positioned behind home plate, and a player from the batting team (the batter) tries to hit the ball with a bat.

  • The members of the batting team bat in a predefined order declared at the start of the game, known as the batting order. When the end of the order is reached, the order wraps around to the beginning.
  • The batter is out if he receives three strikes. A strike is charged if
    • The batter swings at the ball and misses.
    • The ball passes unhit through the strike zone, roughly the region over home plate between the batter’s chest and knees.
    • The batter hits a foul ball, except that a strike is not charged if it would be the third strike.
  • If the catcher fails to catch the third strike, then complicated rules apply. Just enjoy the spectacle.
  • A pitch outside the strike zone that is not swung at is a ball. After four balls, the batter is awarded first base, known as a walk.
  • The batter is also awarded first base if he his hit by a pitch.
  • If the batter hits a fair ball, then we move to the next phase: Running.

Running: After hitting a fair ball, the batter becomes a runner and is forced to advance to first base.

  • A runner in contact with a base is safe from being put out (unless forced off it by the runner behind him), and may advance to the next base at their own risk. A runner who is put out leaves the field.
  • At most one runner may occupy a base. Therefore, after the batter becomes a runner, any runner already on first base is forced to advance to second base to make room for his teammate. This may in turn force a runner on second base to advance to third base, and so on.
  • A runner may not pass the runner ahead of him.
  • A ball is caught if a fielder secures control of the ball before it hits the ground.
  • If a batted ball (fair or foul) is caught, then the batter is put out, and all runners must return to their original bases. After touching their original bases, runners may advance to the next base at their own risk.
  • If a runner is put out, then runners ahead of that runner are no longer forced to advance. This is known as removing the force, which sounds like a Star Wars thing.
  • If a fielder touches (tags) a runner with the ball, or with a glove that in turn holds the ball, and the runner is not touching a base, then the runner is put out.
  • If a fielder holding the ball steps on a base before a runner who is forced to advance or return to that base can do so, then that runner is put out.
  • A fair batted ball that goes over the far boundary fence is a home run, and all runners (including the batter) obtain free passage all the way around the bases to home plate, thereby scoring one run each.
  • Runners may advance on a foul ball only if it is caught. A foul ball not caught causes play to stop.
  • Play also stops if an umpire declares time out, or simply time. It is customary for umpires to grant time upon reasonable request from any player.

Other notes

  • By convention in the United States, spectators at professional games are permitted to keep any balls that go out of play.
  • As a general rule, pitchers are poor batters, and some leagues permit a designated hitter, who is a player who bats in place of the pitcher. A great way to start an argument is to propose that the designated hitter be abolished or expanded.
  • Substitutions may be made any time play has stopped. The player who has been replaced may not return to the game.
  • For various infractions, the umpire may award bases (to penalize the fielding team) or declare players out (to penalize the batting team). Some infractions are not enforced automatically, but require an explicit appeal.
  • There are various limiting rules to close loopholes. I can think of two that may arise in a typical game.
    • The infield fly rule is famous for the fact that few people actually understand it. So don’t worry that you don’t understand it either.
    • A bunted foul ball is a strike, even if it is the third strike. A bunt is a ball hit by gently tapping with the bat.
  • Another famous rule is the balk rule. This rule governs how the pitcher may throw the ball, and it is so complicated that even baseball enthusiasts throw up their hands in despair (see GIF number 18).
  • Although runners typically advance only when the ball is hit, they can try to advance to the next base any time the ball is in play. Doing so without the ball being hit is called a stealing a base.
  • The rules do not dictate where fielders stand (aside from the pitcher and catcher), but there are traditional locations for each. In recent years, teams have been experimenting with nontraditional positioning. Another way to start an argument is to say that nontraditional positioning is either a breath of fresh air or a travesty which should be banned.

This weekend, I’ll be taking some of my friends to their first baseball game. We’ll see how that goes.

Bonus chatter: Baseball is an old game, and its history sheds light on some of the rules and terms. For example, in the 1850’s, batter were permitted three attempts to strike the ball, but were under no pressure to do so. Batters would just stand there until a pitch was thrown to their liking. To remedy this, the umpire was given the authority to announce a strike, meaning, “That was a good pitch, so even though you did not attempt to strike the ball, I will act as if you did.” This eventually led to the formalization of the strike zone.


Discussion is closed. Login to edit/delete existing comments.

  • Louis Yovin 0

    Who’s on first?

  • cheong00 0

    May want to add that “Whenever the batter is awarded a base, all preceding runners are forced to advance, including the runner on third base who is forced to home plate to score a run” next to the line about “walk” for the sake of completeness.

    • Raymond ChenMicrosoft employee 0

      It is not the case that all preceding runners are forced. They are forced only if there are no intervening empty bases.

  • Jonathan Smith 0

    No mention of the existance of field specific ground rules as an ‘Other Note’?  Always interesting when some field specific event happens.

    • Raymond ChenMicrosoft employee 0

      Interesting, but unlikely to occur in a typical game, and even aficionados of the game don’t understand all the ground rules.

  • David Walker 0

    “An inning is completed when each team has had a turn at bat and a turn in the field.”
    That is not correct.  A half-inning is completed when the team who is on offense that half-inning has three OUTS recorded against it.  Two half-innings make one inning.  🙂 
    Your text makes it sound like all players from one team get to bat.
    My husband thinks that one team should have 27 outs, following by the other team having 27 outs.  That is interesting, but it would be a different game.  “Runners left on base” are a big part of any game.

    • Raymond ChenMicrosoft employee 0

      “When three players from the batting team have been put out, the fielding team comes to bat, and the batting team takes the field.” So you don’t get to bat indefinitely.

      • Joe Woodbury 0

        “So you don’t get to bat indefinitely.”
        You do if you avoid getting three outs. (In some, all?, little league and inning ends when all players have batted, even without three outs.)

  • David Walker 0

    Also, to really enjoy the game, you need to understand the rare but exciting “triple play”.  🙂  
    Baseball proceeds at its own leisurely pace, with intervals of exciting things happening.

    • Simon Clarkstone 0

      Sounds rather like cricket then. Doesn’t last 5 days though.

  • Richard Hsu 0

    “A player on the batting team scores a run by touching all the bases in sequence, ending at home plate.”
    Does he get to bat again? or he has to leave and the next batter faces the pitcher?

    • Raymond ChenMicrosoft employee 0

      The batters take their turn in the declared batting order. Once the batter hits a fair ball (or strikes out or is awarded a base), the batting phase is over.

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