Double
A hit that gets the batter to second base.
What it actually is. A hit that reaches second base, most often a ball into a gap or off a wall.
What a scout reads off it. Doubles are the truest sign of hard contact in the whole box score. Home runs need the ball to leave, which depends on the park and the air; a double just needs the ball hit hard into space. A young hitter whose doubles are climbing is usually a young hitter whose home runs are about to.
Where the lines are. Fifty doubles is a season people remember. Earl Webb's 67 in 1931 is the record and has not been threatened in ninety years.
Batter's Eye: look up anything in baseball