Ragozin — Tsvetkov

Chigorin MemorialMoscow, 1947

• Viacheslav Ragozin (1908–1962)Soviet grandmaster (1950) and the second World Correspondence Champion (1956–1959). He was Botvinnik's long-time sparring partner and second, and the Ragozin Defence in the Queen's Gambit bears his name.
• Aleksandar Tsvetkov (1914–1990)Bulgarian international master (1950) and six-time national champion (1938–1951). He was his country's first international master and played at four Olympiads.

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1. 14.
2. A typical method against hanging pawns. Black cannot defend the c5 pawn with another pawn, and so loses control of the central d4 square. This turned out to be decisive
3. 14.
4. AfterWhite's pieces would take up excellent attacking positions
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11. White has gained a clear positional advantage, taking the c-file and the d4 square. Black is left with an isolated pawn in the center, which becomes a weakness in the endgame

Undermining hanging pawns paid off. But of course, this tactic is not worth playing when the side with the hanging pawns gets a strong passed pawn out of it.