The 2023 Major League Baseball season (MLB) began on March 30. The 93rd All-Star Game was played on July 11, hosted by the Seattle Mariners at T-Mobile Park in Seattle, Washington, with the National League winning, 3–2. The regular season ended on October 1, and the postseason began on October 3, with a potential World Series Game 7 scheduled for November 4. This season saw the introduction of several rule changes: in an effort to create a quicker pace of play, a pitch clock was introduced along with other minor changes, while limits on defensive shifts and larger bases were also introduced.
Schedule
On August 24, 2022, Major League Baseball released its 2023 schedule. There are 162 games scheduled for all teams. This will be the first MLB season of a new balanced schedule in which every team will play each other at least once, similar to the NBA and NHL. The new balanced schedule includes 13 games against their division rivals, totaling 52 games. Each team will play six games against six opponents and seven games against four opponents in the same league for a total of 64 games. Each team will also play 46 interleague games, including a four-game home-and-home series against their designated interleague rival.
As part of the "MLB World Tour", the San Francisco Giants and the San Diego Padres played a two-game series at Alfredo Harp Helú Stadium in Mexico City on April 29–30, while the St. Louis Cardinals and the Chicago Cubs played a two-game series at London Stadium in London on June 24–25. The 93rd All-Star Game was played on July 11, hosted by the Seattle Mariners at T-Mobile Park in Seattle. The MLB Little League Classic featured the Philadelphia Phillies against the Washington Nationals on August 20. The Nationals won the game 4–3.
Opening Day, March 30, featured all thirty teams, the first time since 1968 that every team has started their season on the same day.
The MLB at Field of Dreams game will not be held due to the construction of a new youth baseball and softball complex at the Field of Dreams site near Dyersville, Iowa.
Rule changes
On September 8, 2022, MLB announced a set of rules changes that will take effect in 2023. A pitch clock was introduced, with these requirements: A standardized period of 30 seconds between batters within each half-inning. A timer between pitches of 15 seconds with the bases empty, and 20 seconds with at least one runner on base. The pitcher must start his motion before the expiration of the pitch clock. A violation will result in an automatic ball. The batter must be in the box and alert to the pitcher with no less than eight seconds remaining. A violation will result in an automatic strike. With runners on base, the timer resets if the pitcher attempts a pickoff or steps off the rubber (collectively called a "disengagement"). Only two disengagements are allowed per plate appearance; however, this count resets if a baserunner advances. Mound visits, injury timeouts, and offensive team timeouts do not count against this. On a third disengagement, an unsuccessful pickoff attempt will cause that runner to advance one base. If a team has used up all of its allowed five mound visits by the ninth inning, it receives an extra visit in the ninth. Umpires can provide extra time if circumstances warrant. Infield shifts are restricted: The defensive team must have no fewer than four players in infield positions, with at least two on each side of second base. All infielders must have both feet on or inside the outer edge of the marked infield while the pitcher is on the rubber. Infielders cannot switch sides of the infield before a pitch is released. If infielders are improperly aligned at the time of the pitch, the offensive team may choose to accept the result of the play or receive an automatic ball. All three bases will increase in size from 15 to 18 inches (38 to 46 cm).