fair ball
Baseball
noun
1A pitch delivered within the strike zone (now rare ).
2A batted ball that keeps within the two foul lines as it goes past first or third base, or that comes to rest or is touched by a fielder between the foul lines in the infield.
Origin
Mid 19th century; earliest use found in The Spirit of the Times: a chronicle of the turf, agriculture, field sports, literature and the stage.