The Flow of the Game

BASEBALL DIAMOND.  Click to enlarge

A game begins with the first inning.  Each inning is divided into two halves called the top (first half) and bottom (second half).

The top of each inning always starts with the visiting team on offense batting first, while the home team is on defense and takes the field, meaning that they spread out across the field to take their respective positions as you see in the image on the right.

The visiting team's pitcher (represented as the "P" in the center of image at the right) will begin by throwing a ball over home plate towards the catcher ("C"), aiming for the strike zone.  The strike zone is an area over home plate where the ball is deemed to be hittable.

Meanwhile, one of the players on the visiting team will begin at bat as the "batter" or "hitter," meaning that he will line up next to home plate and try to hit balls thrown by the pitcher.  Each time the pitcher throws or pitches, the batter may choose whether or not he wants to swing at the ball.

The batter should choose not to swing at the ball if he thinks that the pitcher's throw will fall outside of the strike zone.  If he is correct, this is called a ball.  A hitter who correctly identifies and doesn't swing at four balls is able to automatically advance or "walk" to first base.  If, however, the batter is incorrect, then this is functionally the same as if he had swung at the ball and missed, i.e., it counts as a strike.  Identifying and hitting the ball is tricky because the pitcher will throw a variety of different types of pitches.  Some of the most common pitches are fast balls (as fast as a pitcher can throw, up to 100 mph), breaking balls or curve balls (balls that will follow a curved path towards the plate), and changeups (balls that look like fast balls, but will slow down once they approach the plate).

BASEBALL STRIKE ZONE. Click to enlarge.

Each time the batter swings and is not able to hit the ball or he hits the ball and it falls outside of the foul lines (i.e., a foul ball), it is called a strike.  If the batter accumulates three strikes, then he is striked out, meaning that he is out for the inning.   However, it is notable that a foul ball can never be a third strike, which means that a batter with two strikes can continue to hit foul balls until he swings and misses to accumulate a third strike or he is able to advance to first base.

If the batter is able to hit the ball with a bat between the white foul lines and beyond the outer wall of the park (or outfield wall) this is called a home run.  This means that the batter and any of his teammates who are safe on bases are now able to automatically advance to home plate to score runs.

If the batter is able to hit the ball between the white foul lines, but it stays within the park walls, then the ball is at play, and the hitter is now a base runner.  The base runner may start running towards first base and attempt to advance around all of the bases for a run, before the end of the half of the inning.  On his way to home plate, he may stop on any of the bases, where he is safe.

When the ball is at play, the home team will be on defense trying to get the hitter out in two additional ways:

  1. Flied Out:   After the batter hits the ball, a player on defense catches the ball before it bounces on the ground.
  2. Put Out:  A player on defense touches (or "tags") the base runner with the baseball when he is not safe on a base. In certain circumstances, a defensive player may also simply touch the base rather than the base runner.  This happens if the base runner is between bases and cannot retreat clockwise to the closest base, because one of his teammates is occupying it.

Once the base runner stops and is safe on a base or is called out, one of his teammates will be next at bat and will repeat the process.  While the ball is at play, all base runners can continue trying to advance around the bases towards home plate to score runs, but no player can pass one of his teammates on his way to home plate.  

Some players may try to steal bases by running to the next available base, while the pitcher has the ball and is preparing to pitch to the next batter.

SAMPLE BASEBALL SCOREBOARD.  Click to enlarge.  

When three players are called out, then the top of the inning ends and the bottom of the inning begins.  The bottom of each inning is played with the home team at bat on offense and the visiting team on defense.

The game will continue in this fashion for nine innings.  The team with the most runs at the end of the game wins.  

If at the end of the top of the ninth inning, the home team is in the lead, the two teams do not need to play the bottom of the ninth inning, because the home team has already won!