Cook in chess: unintended solutions and problem cooks

Cook

Definition

In chess composition, a cook is an unintended solution that “spoils” a problem, study, helpmate, or proof game. If a composed position is supposed to have a unique way to satisfy its stipulation (for example, a single key move in a mate-in-two), but another line also meets the stipulation, the composition is said to be cooked (unsound). By contrast, a dual is an unintended choice within a correct solution line; a cook typically means there is an extra solution starting from the initial position.

In over-the-board (OTB) analysis and opening theory, to “cook” a line means to refute or seriously challenge it, often by finding a new resource or novelty that busts established analysis.

Usage in Chess

Problemists use cook in two principal ways:

• Compositions: “This mate-in-two is cooked—there’s a second key.” A cooked problem fails the standard of being sound (unique solution and clean thematic play).
• Analysis: “That published variation was cooked by a new engine line.” Here, cook is a synonym for “refute” or “bust.”

Important related terms include Dual, Sound, Unsound, Helpmate, Selfmate, Seriesmover, Proof game, Endgame study, Tablebase, and Syzygy.

Strategic and Historical Significance

Soundness is a bedrock principle of chess composition. Judges at problem tourneys penalize or disqualify entries that are cooked, and many famous tasks (e.g., the Babson task or AUW problems) required decades of refining to remove cooks.

• Engine era: Specialized solvers (e.g., Popeye, WinChloe) and endgame Tablebases (e.g., Syzygy, Nalimov) have cooked numerous classic studies by revealing hidden resources.
• Opening theory: Historically, “to cook a line” meant to refute a published analysis. Modern engines routinely “cook” human notes, reshaping repertoire books and online Theory.

Famous anecdote: The celebrated Saavedra underpromotion motif arose because an earlier published study was discovered to be incorrect—effectively “cooked.” The correction unveiled the winning underpromotion, turning a flaw into one of endgame theory’s most iconic ideas.

Types of Cooks (in Composition)

• Second key cook: A directmate claiming a unique key has a second first move that also solves.
• Alternate solution cook: In a helpmate/selfmate, an extra full solution exists beyond the intended set.
• Study cook: A study claiming “win” or “draw” turns out to have the opposite evaluation, or has multiple winning/drawing routes when uniqueness was intended.
• Proof game cook: A shorter or different reconstruction reaches the diagram than the composer intended.

Note the distinction: a Dual is an unintended choice inside a solution line; a cook is an unintended solution from the start position that satisfies the stipulation.

Examples

Example A (composition, conceptual): A directmate “Mate in 2” is announced. The composer intended 1. Qh5! with threats and precise replies. Later analysis finds that 1. Qg4! also forces mate in two against all defenses. Because there are two keys from the start position, the problem is cooked (unsound). If, instead, 1. Qh5! were still the only key but one variation after a Black defense had two mating continuations, that would be a dual, not a cook.

Example B (opening analysis “cook”): Bobby Fischer’s famous 1961 article “A Bust to the King’s Gambit” proposed lines that “cooked” the traditional view of the opening. A representative sequence he highlighted was:

Line: 1. e4 e5 2. f4 exf4 3. Nf3 d6 4. d4 g5 5. h4 g4 6. Ng1 Bh6, arguing that Black obtains a strong, even winning, initiative. Later engines have revisited and “cooked” parts of Fischer’s analysis, showing that the verdict is more nuanced.

Interactive line viewer:

Example C (study “cook” and correction): In the late 19th century, a published king-and-pawn versus rook study was shown to have an incorrect claim; a reader, Saavedra, found a correction that introduced the immortal underpromotion to a rook. This story is often cited to show how cooking a study can lead to deeper, more beautiful truth.

How Cooks Are Found

• Human analysis: Problemists “cook-hunt” by searching for extra keys or unintended solutions, often starting with tries that look close to the main idea.
• Engines and solvers: General engines (Stockfish, Leela) and dedicated problem solvers test uniqueness and stipulations. Endgame Tablebases are definitive in material-limited positions.
• Thematic pressure points: Symmetry, idle pieces, and extra tempo often signal potential cooks.

How Composers Prevent or Repair Cooks

• Cook-stoppers: Adjust a unit (shift a king, add/remove a guard, change a pawn from a2 to a3) to eliminate unintended solutions.
• Economy and precision: Avoid redundant force that could enable extra keys; refine until the solution is unique and thematic.
• Retheming or restipulating: Switch to a different stipulation (e.g., from directmate to Selfmate/Helpmate) or adjust move-length to preserve the idea without cooks.
• Verification: Run multiple solvers and, where relevant, consult Tablebases for endgame clarity.

Practical Tips (for Solvers and Composers)

• For solvers: If you suspect a second key in a “mate in n,” try candidate keys that deliver the same threat but change the move-order or guard a different square.
• For composers: Before submitting, test for alternative keys, check for quiet secondary solutions, and examine symmetrical shifts that might create extra routes.
• For analysts: In opening notes, always ask “What’s the resource?” Fresh engine searches at depth or with different settings often “cook” trusted annotations.

Interesting Facts and Anecdotes

• Vocabulary: The phrase likely entered chess slang in the 19th century among problemists—“to cook” meaning “to spoil” a carefully prepared dish.
• Beauty through correction: Several famous ideas (like the Saavedra underpromotion) were born from cooks that forced a better, sounder re-composition.
• Engine era humility: Many classic endgame studies by great composers were later cooked by precise tablebases—reminding us that soundness is provisional until fully verified.

Related Concepts

• Dual
• Sound and Unsound
• Theme, Key, Try, Set play
• Helpmate, Selfmate, Seriesmover, Proof game
• Endgame study, Tablebase, Syzygy

Quick Usage Examples (OTB and Problems)

• “The helpmate has two solutions instead of one—cooked.”
• “Adding a black pawn on a6 stops the extra key and de-cooks the problem.”
• “That line in the Najdorf was cooked by a new novelty on move 17.”

SEO Summary

Cook in chess means an unintended solution that makes a composed problem or study unsound. Problem cooks include extra keys, alternate solutions, or wrong evaluations. In opening theory, to cook a line is to refute it. Learn how cooks arise, how to find them with engines and tablebases, and how composers repair positions to restore soundness. Related terms: Dual, Sound, Unsound, Helpmate, Selfmate, Proof game, Endgame study.