how to clue dangerous cards

[Noah1620]

I'm noticing a lot of Hanabi players immediatly play a card when you clue them a color or number. But what if a number is in danger because it's been already played? For example the three of white has been already played. Then how to clue that it shouldn't be discarded?

[Jellby]

First of all: don't clue it until it is actually in danger of being discarded. Don't clue if it's not the rightmost unclued card (a.k.a. chop). Don't clue it if the player has a clued (or finessed/bluffed) card to play. You don't need to clue it (but you can) if you can force 8 tokens to the player, so they cannot discard.

Typically, at least on BGA, a number clue touching the chop is considered a save clue and not a play clue by default. Why number and not color? Because the first cards we need to save are 5s, which can be clearly identified with a number and not a color. Also a number clue is always possible even with black powder.