How do I decide between a hit and an error?

Hit (rule 9.05(a)): score a base hit when the batter reaches first or any later base safely on a fair ball that:

1. settles on the ground, touches a fence before a fielder touches it, or clears a fence;
2. is hit with such force, or so slowly, that no fielder has an opportunity to make a play;
3. takes an unnatural bounce, or touches the pitcher's plate or a base before a fielder touches it, so that a fielder cannot handle it with ordinary effort;
4. has not been touched by a fielder and is in fair territory when it reaches the outfield, unless it could have been handled with ordinary effort;
5. touches a runner (runner is out) or an umpire before a fielder touches it; or
6. is fielded and the fielder unsuccessfully tries to put out a preceding runner, when in the scorer's judgment the batter-runner would not have been out at first by ordinary effort.

Always give the batter the benefit of the doubt; a safe course is to score a hit when exceptionally good fielding fails to produce an out.

Error (rule 9.12): charge an error to a fielder whose misplay (fumble, muff or wild throw) prolongs a batter's time at bat, prolongs a runner's presence on the base, or lets a runner advance. Slow handling without a mechanical misplay is not an error, and mental mistakes or misjudgments are not errors unless a rule says so. A fielder need not touch the ball: a grounder through his legs, or a pop fly that falls untouched, is an error if he could have handled it with ordinary effort. A decisive error prolongs the batter's or runner's life when the player should have been out; write it in upper case red letters followed by the fielder's position number.