Here are some fundamental numbers and measurements for understanding your typical ballgame!
There are 9 innings in a standard professional baseball game. A game might be shorter if called due to weather (e.g. rainouts) or a failure in a stadium’s lighting system. In those situations, if five full innings have been played, or the home team is leading at four-and-a-half innings played, then the game qualifies as a complete, regulation contest. A game may also run longer than nine innings if the score is tied at the completion of the bottom of the ninth.
Each inning is divided into 2 half innings. The away team bats in the top half of the inning (the first half), and the home team bats in the bottom half of the inning (the second half).
Each team gets 3 outs in its half inning of offense (batting), for a total of 6 outs per full inning.
Each team is required to have 9 players in its batting order, as each player on the field playing defense also takes part in the offense. The exception to this is cases where the designated hitter is used to hit in place of another player (usually the pitcher). Whenever use of the designated hitter is permitted, only one is allowed in each team’s batting order.
When batting, a hitter gets 3 strikes to try to put the ball into play. A strike is when a delivered pitch passes through the strike zone and/or the batter swings and misses. When three strikes accumulate, the batter is out.
If a batter accumulates 4 balls, he may “walk” to first base. A ball is a pitch that is outside of the strike zone that the batter does not swing at.
The distance between bases is 90 feet.
The distance from the pitcher’s rubber to home plate is 60 feet, 6 inches.
The distance from home plate to the outfield fence varies from ballpark to ballpark, and even varies at different points of the outfield within a given ballpark. MLB distances range from 302 feet to 435 feet.
The dimensions of the batter’s box are 4 feet by 6 feet. A batter is required to stay within the batter’s box during his at-bat.
The pitcher’s mound measures 18 feet in diameter. The height of the mound has changed throughout history, but today the top of the pitcher’s rubber can be no higher than 10 inches above the level of home plate.
The width of the warning track is 10 to 15 feet. The warning track is the strip of dirt just in front of the outfield fence, whose existence is intended to warn an outfielder when he is getting close to the fence while tracking down a fly ball.