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Number Guess
Number Guess is a deduction game in the Bulls and Cows tradition, a pencil game that predates the colored-peg game Mastermind by decades. One side picks a secret number with no repeated digits, and the other cracks it using feedback after each guess, narrowing the possibilities with logic.
Number Guess Rules
One player (or the computer) secretly chooses a number, classically four digits with no repeats. The other player tries to guess that exact number, digit by digit, in as few attempts as possible.
After each guess the codemaker reports two counts: 'bulls' are digits that are correct and in the right position, and 'cows' are digits that appear in the secret but in a different position. For example, guessing 1234 against 1357 yields one bull and one cow.
Use those clues to refine the next guess. The game ends when you score four bulls — the full number is correct — and your score is the number of guesses it took, so fewer is better.
Number Guess Strategy & Tips
Open with all-different digits
Start with guesses that use ten distinct digits across your first two or three tries, such as 1234 then 5678. This quickly tells you which digits are in the secret before you worry about order.
Separate bulls from cows
Compare guesses that differ in only one position. The change in bull count between two near-identical guesses pinpoints exactly which digit belongs in that slot.
Eliminate, then arrange
First nail down which four digits are present using the total of bulls plus cows. Only once the digit set is known should you spend guesses sorting them into the right positions.
Track every clue on paper
Keep a written log of each guess and its bull/cow result. Cross-referencing past feedback rules out impossible arrangements and prevents wasting a guess on a contradiction.
Frequently Asked Questions
What is the difference between a bull and a cow?
A bull is a digit that is both correct and in the right position. A cow is a digit that is in the secret number but sits in the wrong position.
How is this related to Mastermind?
Number Guess uses digits where Mastermind uses colored pegs, but both give right-place and right-color/wrong-place feedback. Bulls and Cows is the older pencil version.
Can the secret number have repeated digits?
The classic rules forbid repeats, which keeps the bull and cow counts unambiguous. Some variants allow repeats, making the deduction harder.
What is a good number of guesses?
With solid logic most four-digit games are cracked in five to seven guesses. Optimal strategies can guarantee a solve in about seven attempts for the no-repeats version.