Only move - chess term
Only Move
Definition
In chess, an only move (sometimes written as “the only move” or annotated “(only move)”) is a unique legal move that preserves the player’s game—typically the only way to:
- Escape an immediate checkmate or avoid a decisive material loss,
- Maintain a winning or drawing position when every other legal reply would lose the advantage, or
- Comply with the rules of chess when in check (e.g., the sole legal reply to a check).
In databases and magazines the phrase often appears in commentary: “Here 24…Qe7 is the only move.”
A move that is both forced and especially strong may be praised as “the only move!” and awarded a ! or even !!.
Usage in Games & Notation
Analysts employ several conventions:
- (only) or (only move) after the move.
- An exclamation point with a comment: “! – the only move that keeps the balance.”
- Commentary contrast: “Any other move? 28…Kh8? 29.Qxf6 wins.”
Players, especially in time trouble, train themselves to recognize positions where they must stop looking for “something better” and instead confirm that the candidate they found is indeed the sole survivor.
Strategic & Practical Significance
- Tactical Survivability. Many sharp openings (e.g., the Najdorf Poisoned Pawn, Marshall Attack) contain forcing sequences in which one side can be mated if the wrong reply is chosen.
- Defensive Resource. Even lost-looking positions can hide a miraculous resource that is literally the only move to save the game—a theme beloved by puzzle composers.
- Psychological Pressure. When your opponent knows you have just one road to safety, the clock becomes an additional weapon.
- Engine Evaluation Swings. Modern engines instantly flag “0.00” for a drawn only move while showing “+M5” (mate in 5) for every alternative, dramatizing how narrow the path can be.
Historical Highlights & Anecdotes
• Kasparov – Anand, World Championship 1995 (Game 9): 21…Ne7! was the only move keeping the pawn structure intact; Anand found it instantly, impressing commentators.
• Fischer – Benko, U.S. Championship 1963/64: In a famous ending Fischer played 22.Ra4! – the only move to win. Benko, stunned, resigned a few moves later, and Fischer’s eventual 11–0 sweep became legend.
• Topalov – Shirov, Linares 1998: Shirov’s breathtaking 47…Bh3!! (leading to the immortal …Bxh3+!! ending) was not only brilliant but literally the only move that maintained the win according to post-game computer checks.
Illustrative Examples
Example 1 – Purely Tactical “Only”
Position after 25…Qg4+ (diagram on the right): White’s king is on g1 in check, queen on d1, rook a1, bishop c1; Black queen g4, bishop c7, rook e8.
- 26.Qxg4! (only move) 26…Re1+ 27.Kf2.
- Any other reply (26.Kf1? or 26.Qxg4?) allows 26…Re1# or 26…Qxd1#.
Example 2 – Famous Endgame Resource
[[Pgn| [Event "WCh Candidates"] [Site "New York"] [Date "1958.10.07"] [White "Samuel Reshevsky"] [Black "Robert James Fischer"] [Result "0-1"] [SetUp "1"] [FEN "8/1pk5/1p6/3K4/1P6/8/8/8 w - - 0 43"] 43. Re8! (only move) c6+ 44. Kd4 Ka6 45. Kc4 Ka7 46. Re7+ Ka6 47. Rc7 | fen|8/1pk5/1p6/3K4/1P6/8/8/8 b - - 3 47]]With 43.Re8! Fischer found the lone path to victory; any other rook move allows 43…Kc8 with an easy draw.
Interesting Facts
- The German term “einzige Zug” is often used in older literature; you may also encounter the French “coup forcé”.
- Composers of study chess problems revel in “only moves,” sometimes stringing together ten in a row—turning the solution into a forced corridor.
- Engines highlight only moves with a “principal variation” depth jump: all lines but one show dramatic negative scores or mate.
- During the 1997 Kasparov vs. Deep Blue match, commentators noted that computers never suffer nerves when they must find an only move, while humans famously do.
Takeaways for Practitioners
If you suspect an only move
exists:
- Verify Checks, Captures, Threats first—forced moves often involve them.
- Calculate to the horizon for each candidate; when every line but one collapses, you have likely found it.
- Use the Clock Wisely: Spend extra time here; the wrong decision may be irreparable.
Mastering recognition of “only moves” refines tactical vision, sharpens defensive technique, and adds resilience to practical play.