In the ballpark and hit one out of the ballpark are two American idioms that seem like they would have opposite meanings, but in fact have definitions that are unrelated. We will examine the meanings of the phrases in the ballpark and hit one out of the ballpark, where these terms came from and some examples of their use in sentences.
In the ballpark refers to something that is a close estimation, an answer or amount that may or may not be the exact correct answer or amount, but is near it. The idea for the idiom in the ballpark stems from the American game of baseball, and the field of play housed inside the stadium that consists of an infield and and outfield. That stadium and field is considered the ballpark. During the early 1960s, when the Air Force and NASA were conducting tests concerning space travel, the area in which they hoped to land test missiles or capsules was called the ballpark. Any landing within this designated area of several hundred miles was considered in the ballpark, and close enough to the target to be considered a success. American baseball is the source of many idioms, such as out of left field, have all one’s bases covered and get to first base.
To hit one out of the ballpark means to score a resounding success, to accomplish a significant achievement. The term hit one out of the ballpark also comes from American Major League Baseball and minor league baseball and scoring home runs. A home run is scored when the batter hits the ball with sufficient force to allow him to run around all three bases and into home plate before the opposing team can recover the ball and throw it into home plate. Usually, in order to score a home run the batter must hit the ball with sufficient force to propel it out of the park, where it is irretrievable by the opposing team. To hit one out of the ballpark is therefore a resounding, unequivocal success. Note that in both instances, the word ballpark is one word, not two words as in ball park.
However, by spring of this year, enough money had been raised — in the ballpark of $25,000, Bach estimated — for the bridge to be built. (The New Canaan News)
This IPO comes a few days after the last tech IPO hit one out of the ballpark, a company called Nutanix. (The Business Insider)