Major League Baseball rules

Major League Baseball (MLB) is played between two teams of nine players each over nine innings. Teams alternate between offense (batting) and defense (fielding), aiming to score the most runs by the end of the game. Unique to MLB, the American League and, since 2022, the National League both use the designated hitter (DH) rule, allowing a player to bat in place of the pitcher without taking the field.

Game Structure

Field: The field consists of an infield diamond with four bases (first, second, third, and home plate) and an outfield. Bases are 90 feet apart, creating a square shape.
Innings: MLB games have nine innings, each split into a top and bottom half. The visiting team bats first (top half), and the home team bats second (bottom half). If the game is tied after nine innings, extra innings are played until one team leads at the end of an inning.

Scoring

Runs: A run is scored when a player, starting at home plate, advances around all bases and returns to home plate without being put out by the defense.
Hits: Batters aim to hit the pitched ball into fair territory, allowing them to reach base or advance runners. The goal is to accumulate hits to eventually score runs.

Batting and Baserunning

At-Bats: Batters face pitches from the pitcher and attempt to reach base through hits, walks (four balls pitched outside the strike zone), or other means such as being hit by a pitch.
Outs: Each team has three outs per half-inning. Players are out for reasons like a strikeout (three strikes), fly-out (a caught ball in fair or foul territory), or tag out (tagging a runner with the ball while they are off base).
Stealing: Runners may attempt to advance to the next base during the pitch delivery in a tactic known as “stealing.” The defense can try to throw the runner out if they attempt this.

Designated Hitter (DH)

Purpose: The DH rule allows a player (designated hitter) to bat in place of the pitcher, who is typically a weaker batter. The DH only bats and does not field a defensive position.
Usage: The DH rule is standard in both the American League and the National League, and the designated hitter must be chosen before the game begins. Once a player is designated as the DH, they can only take over a fielding position if their team forfeits the DH spot for the remainder of the game.

Pitching and Defense

Strike Zone: The strike zone is an area above home plate from the batter’s knees to the midpoint of their torso. Pitches within this zone count as strikes if not swung at, while pitches outside the zone count as balls.
Pitching Count: The count refers to the number of balls and strikes a batter has. Four balls result in a “walk” to first base, while three strikes result in an out.
Fielding: The defense aims to prevent runs by getting batters or runners out. Fielders catch fly balls, throw out runners, and tag players to accomplish this.

Penalties and Violations

Errors: An error occurs when a fielder misplays a ball, allowing a batter or runner to advance or reach base. Errors affect a player’s fielding statistics but do not directly affect the game score.
Balk: A balk is an illegal pitching action that deceives the batter or runner. When called, runners advance one base.

Time and Substitutions

Pitch Clock: MLB has implemented a pitch clock to speed up play, requiring pitchers to start a pitch within a set time.
Substitutions: Once a substitute player enters the game, the replaced player cannot return. This rule applies to both fielders and the designated hitter.

Extra Innings and Tiebreakers If the game is tied after nine innings, extra innings are played until one team leads at the end of an inning. MLB uses the “ghost runner” rule, placing a runner on second base at the start of each extra inning to encourage scoring.

The goal is to score more runs than the opposing team through strategic plays, pitching, and batting, with the designated hitter rule providing flexibility in lineup strategy for both leagues.

ChatGPT Prompt: Now, please provide a one-page synopsis of the rules and regulations of Major League Baseball... Could you please repeat the one page synopsis of the rules and regulations of Major League Baseball, but include the concept of the designated hitter?