Baseball, by the Rules
For more examples, click here.
Fly Ball Single
A batter advancing to first base on a base hit, no matter where the ball is hit, and provided there's no error on the play, is called a "single". There are a lot of variables that can add up to a fly ball single, mostly revolving around where the ball is hit, how hard the ball is hit, where the defenders are positioned, etc.
This may be a good time to restate that a lot of what might look like “errors” won’t be called as such unless a defender actually gets a glove on it. So, imagine a pop up that’s set to come down somewhere behind the pitcher’s mound. A whole bunch of infielders run in to catch it, but no one takes charge, and everyone eventually assumes that someone else has it… but no one else has it. It falls in. That’s a single, and it counts every bit as much as a softly-hit line drive that falls in front of the right fielder.
On this type of play, there is a slim chance that the batter will not be content with a mere single, but will attempt to stretch the play into a double by advancing to second base, in which case the defense will have a chance to make a play. Otherwise, the runner will take first, and the defense will adjust accordingly as they prepare for the next batter.