Walk-off homer

In baseball, a walk-off home run is a home run that ends the game. It must be a home run that gives the home team the lead (and consequently, the win) in the bottom of the final inning of the game. Thus the losing team (the visiting team) must then "walk off" the field immediately afterward, rather than finishing the inning. The winning runs must still be counted at home plate. Because the home team always bats last, any kind of "walk off" scenario, which ends the game, can only be accomplished by the home team.

Although the concept of a game-ending home run is as old as baseball, the adjective "walk-off" attained widespread use only in the late 1990s and early 2000s.

The first known usage of the word in print appeared in the San Francisco Chronicle on April 21, 1988, Section D, Page 1. Chronicle writer Lowell Cohn wrote an article headlined "What the Eck?" about Oakland reliever Dennis Eckersley's unusual way of speaking: "For a translation, I go in search of Eckersley. I also want to know why he calls short home runs 'street pieces,' and home runs that come in the last at-bat of a game 'walkoff pieces' ..." Although the term originally was coined with a negative connotation, in reference to the pitcher (who must "walk off" the field with his head hung in shame), it has come to acquire a more celebratory connotation, for the batter who circles the bases with pride with the adulation of the home crowd.

Sportscasters also use the term "walk-off hit" if any kind of hit drives in the winning run to end the game. The terms "walk-off hit by pitch", "walk-off walk" (a base on balls with the bases loaded), "walk-off wild pitch", "walk-off reach-on-error", "walk-off steal of home", "walk-off passed ball", and "walk-off balk" have been also applied, and the latter has been dubbed a "balk-off". It is a separate stretch of the term to call a hit a walk-off when what ends the game is not the hit but the defense's failure to make a play (as in a single with a possible out at the plate). The day after Eric Bruntlett pulled off a game-ending unassisted triple play for the Philadelphia Phillies against the New York Mets on August 23, 2009, the Philadelphia Daily News used the term "walk-off triple play" in a subheadline describing the moment.

...
Wikipedia