Should you try to shoot the moon?

You need two things: the ability to win tricks on demand, and no cards that force you to lose one. That means long, high hearts (Ace-King-Queen with length is the classic core), aces and kings in the side suits, and very few low cards that opponents can duck under. If you find yourself hoping opponents make mistakes, the hand does not qualify - fold the idea and play for low.

The downside is not symmetric. Succeed and you swing the game: zero for you, 26 for everyone else. Fail after committing - once you have won a pile of hearts - and you usually eat 20 or more points, plus you have burned the high cards you needed for defense. All it takes to stop you is one opponent grabbing a single heart, and good opponents will spend a high heart early precisely to do that.

Moons succeed most often when opponents are distracted - dumping points cheerfully, assuming nobody would dare. They fail when someone spots the pattern early: a player winning tricks they should be ducking. Late in a game the calculus shifts too; a player near the 100-point line may gamble on a thin moon because a normal hand loses anyway. Know the mechanics cold before you leap - see how the moon works.