What is a leech card?

A leech is a card you keep failing however many times it comes back. It eats review time, never improves, and it is almost always a problem with the card rather than with your memory.

The name is apt. The card keeps returning, keeps costing you a slot in every session, and gives nothing back.

Why cards become leeches

• It carries more than one idea. You get half of it right, fail the whole card, and repeat that forever.
• The question has several defensible answers. You answer correctly, the back of the card says something else, and you mark yourself wrong.
• It is nearly identical to another card. You are not failing the fact, you are failing to tell two cards apart. This is the most common cause and the least obvious.
• You never understood the material. A card can test recall but it cannot install understanding. Some cards fail because the underlying concept was never learned, and no scheduling algorithm fixes that.

What to do

Rewrite it, and usually that means splitting it. A card testing three things becomes three cards, each with one answer. A card that collides with its neighbour needs a cue that distinguishes them.

If the concept underneath is missing, go back to the source material for ten minutes. A card is a retrieval tool, not a teaching tool.

If it is genuinely trivia you do not need, delete it. Deleting a card that is not earning its place is a legitimate decision, not a failure.

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