Winning openings in rectangular Chomp
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Can a rectangular Chomp board have at least three winning first moves? Chomp is the chocolate-bar removal game with one poisoned corner; strategy stealing proves a nontrivial rectangle is winning without identifying which first moves win.
Why it matters and what counts as progress
Why it matters: Strategy stealing establishes a winner without identifying a move; counting winning openings asks for finer finite-game information.
What counts as progress: Find a board with three winning openings and certify their outcomes by exact game-state analysis.
How the problem developed
- 20 Mar 2019 · Problem statement [1]
Thotsaporn Thanatipanonda, reporting Doron Zeilberger and Shalosh B. Ekhad's challenge Recorded the second computational Chomp challenge: find a rectangular bar with at least three winning opening moves.
- 11 Aug 2026 · Solution [2]
Jaideep Sai Padhi with a large language model Reported a bar with three winning openings and proved a staircase constraint on winning openings for every Chomp bar.
AI contribution
Solutions to Five Challenge Problems in Enumerative and Algorithmic Combinatorics, with an Account of the Human-Machine Methodology Employed
The 10×42 Chomp bar has exactly three winning first bites, at (5,36), (7,30) and (8,26), by exhaustive exact game-state computation.
Sources
Website timeline
Publication dates and editorial changes.
Claude-assisted computation finds three winning Chomp openings