When a hitter hits a short ground ball to second base, should a runner on third stay at the base or run home?
With two outs: YES in almost all situations.
With less than two outs:
- Last inning / trailing by two or more: NO. You need two points, don't take any risk
- Last inning / one out / on-deck batter is weak / trailing by one, tied game or winning by a few runs: YES. You must evaluate your chance of being safe at home vs a weak batter hitting a hit against a closer.
- Other cases: it depends. Take these factors into account: the score, number of outs, on-deck batter, pitcher, speed of runners, fielding ability / defense positioning.
I always tell my teammates to think of their play in advance (as a runner or as a fielder).