Sequence Lock: count repeated digits only as often as they occur
A three-position example separates exact matches from misplaced copies, then shows how to compare candidate secrets against the complete feedback history.
Worked examples use the Standard board unless a different size is stated. Hard and Expert may change the board dimensions or amount of information to track.
Read two counts, not two lists of positions
Sequence Lock reports exact matches and value-only matches after each submitted guess. An exact match has the correct digit in the correct position. A value-only match has a correct digit in a different position. The feedback does not tell you which particular squares produced either count, so do not attach an exact marker to a favourite position without further evidence.
Repeated digits make that distinction important. The scoring process first removes exact matches from both sequences, then compares how many copies of each digit remain. It counts only the smaller available quantity. A guess containing four copies of a digit cannot receive four matches when the secret contains just one.
Work a three-position teaching example
For explanation, suppose the secret is 1, 1, 2. Guess 1, 2, 1. The first position is exact, leaving a 1 and a 2 in the secret and a 2 and a 1 in the guess. Both remaining copies have partners in different positions. The feedback is therefore one exact and two value-only matches, not three exact matches.
Now compare the same hypothetical secret with 1, 1, 1. Its first two positions are exact. After removing them, the secret has only a 2 left, so the final guessed 1 has no partner. The result is two exact and zero value-only matches. Reusing the same symbol in another slot does not create an extra copy in the secret.
Keep candidates consistent with every earlier guess
When considering a possible secret, score it against each earlier guess as though it were the hidden sequence. It remains possible only if every pair of feedback counts agrees. A candidate that explains the newest row but contradicts an older row must be discarded; the secret does not change between guesses.
For example, one exact plus two value-only against the three-digit guess 1, 2, 1 accounts for all three positions. A compatible secret must contain exactly two copies of 1 and one copy of 2. Its order is still unresolved. The candidate 1, 2, 1 itself would yield three exact matches, so it cannot explain that feedback. Distinguish a known collection of digits from their still-unknown arrangement.
Choose the next question deliberately
A useful guess separates remaining candidates rather than merely looking different. Before submitting it, ask what each possible feedback result would rule out. That small planning step is possible without a countdown, and the previous-guesses list remains available during the current run. There is no automatic candidate notebook or hint button.
Restart clears the displayed history while retaining the same secret, so it does not erase information you already learned. New puzzle changes the sequence, and difficulty changes its length and allowed symbols. Keep observations from different puzzles separate. Solving in fewer guesses on a familiar restarted secret is different from discovering a newly generated one.
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