9090 2023 eng reportzib 0 -- 2023-05-09 -- It has been shown that any 9 by 9 Sudoku puzzle must contain at least 17 clues to have a unique solution. This paper investigates the more specific question: given a particular completed Sudoku grid, what is the minimum number of clues in any puzzle whose unique solution is the given grid? We call this problem the Minimum Sudoku Clue Problem (MSCP). We formulate MSCP as a binary bilevel linear program, present a class of globally valid inequalities, and provide a computational study on 50 MSCP instances of 9 by 9 Sudoku grids. Using a general bilevel solver, we solve 95\% of instances to optimality, and show that the solution process benefits from the addition of a moderate amount of inequalities. Finally, we extend the proposed model to other combinatorial problems in which uniqueness of the solution is of interest. urn:nbn:de:0297-zib-90902 publish Gennesaret Tjusila Mark Turner Mathieu Besancon Mark Turner Thorsten Koch 23-15 Computational methods Mathematical Optimization Koch, Thorsten MODAL-Gesamt Turner, Mark Ruben Applied Algorithmic Intelligence Methods MODAL-EnergyLab UNSEEN Applied Optimization https://opus4.kobv.de/opus4-zib/files/9090/Minimum_Sudoku_Clue_Problem.pdf