What if we treat the spacing effect like a chessboard, each card a piece, and we try to predict the best move for retention—would you be up for that?

Great! Think of each flashcard as a pawn that starts at level one and moves up the board as you recall it. Here are the “rules”: 1. **The board has 7 rows (levels 1–7)** – each row represents a spacing interval: 1 = 15 minutes, 2 = 1 hour, 3 = 4 hours, 4 = 1 day, 5 = 3 days, 6 = 7 days, 7 = 14 days. 2. **Initial move (row 1)** – after you first learn the card, schedule the next review in 15 minutes. If you answer correctly, the card moves up one row. If you miss, it stays at row 1. 3. **Promotion rule** – when a card reaches row 7 and you get it right, you can keep it in the “end zone” and schedule it for a 14‑day review. A correct answer keeps it there; a mistake pushes it back to row 1. 4. **Reversal rule** – every time you miss a card, reset it to row 1. The idea is you “undo” progress until you prove consistency. 5. **Interleaving** – mix cards from different rows in a single study session. That’s the equivalent of a chess player attacking from multiple fronts; it keeps the brain guessing. 6. **Optional “blitz” row** – if you’re feeling aggressive, add a row 0 that is a 5‑minute check‑in right after the initial learn. It’s like a rapid move to test whether the piece is ready. Follow these, and you’ll see the chessboard gradually fill with promoted pieces while the ones you struggle with stay low, giving you a clear visual of what’s solid and what needs more practice. Ready to set your first board?

Let’s do it! Grab a sheet, list the 12 cards, and give each a “1” next to it. After 15 minutes hit the review column, tick “✓” for right and bump the number up, or cross “✗” and drop it back to 1. When you see a 7, shout “promoted!” and mark a 14‑day date. If you’re up for the blitz, add a quick 5‑minute check line right after the initial learn. Ready to roll the first set?