The count in baseball is the number of balls and strikes pitched for the current batter. It is always formatted by the number of balls first then the number of strikes. In the count, there can never be more than three balls or more than two strikes. Once there are four balls or three strikes, the count is not kept anymore since the result of the at-bat has been determined.
Three strikes and the batter is out for a strikeout. four balls and the batter is given a walk for a base on balls. In baseball, the count refers to the current number of balls and strikes during an at-bat. The number of balls is always stated before the number of strikes. When writing the count, there is a hyphen between the numbers. For example, if a batter currently has two balls and one strike, the count would be 2-1.
When talking about the count, you can either say, The count is two and one (with an and between both numbers) or He has a two-one count (listing the numbers without and, but saying count right after). Additionally, if there is a zero in the count, the zero is pronounced as oh. For example, if a batter has three balls and zero strikes, or a 3-0 count, it would be pronounced three-oh count.
The count will only extend up to three for balls and two for strikes. Even if the batter gets four balls or three strikes, the count will never include the four or the three. Once the outcome (walk or strikeout) of the at-bat occurs, the count is no longer used.
You'll sometimes hear various phrases used to describe the count in baseball.