hit into the ground has to pass first base or third base in fair territory to be considered fair originated in response to "fair-foul" hitting of the 1860s and 1870s. Batters would intentionally hit the ball into the ground in fair territory near home plate, at an angle that would send it into foul territory away from the fielders, allowing the batter to reach first base successfully. Dickey Pearce, a well-known and respected player of the era, is credited with inventing the tactic. Effect Fielders can attempt to make an out by catching any ball hit in the air, fair or foul, as long as it is still in play. Balls that leave the field of play, such as by going into spectator areas or the dugouts, are out of play. For balls on the ground, fielders can attempt to make an out on fair balls only. A batted ball that clears the outfield fence in fair territory is a home run. Since 1931, whether such a batted ball is fair or foul is judged on its position when it leaves the field (that is, where it is as it passes over the outfield fence or wall). Previously, the ball had to be "fair when last seen" to be ruled a home run. Also since 1931, the ball must clear the fence or wall on the fly to be a home run; previously, the ball could bounce over and still be considered a home run—such a batted ball is now an automatic double. A foul ball normally counts as a strike unless the batter already has had two strikes assessed against them, in which case the count does not change. Treating foul balls as strikes was adopted by the National League in 1901 and the American League in 1903. There are specific rules for foul tips and foul bunts, which are described below. In slow-pitch softball, a foul ball always counts as a strike, even when the batter already has two strikes. Characterization Major League Baseball (MLB) uses four characterizations for all batted balls put into play: Fly ball A fly ball is a batted ball hit in an arcing manner. For statistical purposes, MLB uses the term "fly ball" for such balls that go into the outfield, and a separate term (pop-up, below) for such balls that stay in the infield. Fielders attempt to catch fly balls on their