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|Full name||Mieczysław Chwojnik|
Ruzhany, Russian Empire
Tel Aviv, Israel
Mieczysław (Mendel) Chwojnik, later known as Dr. Menachem Oren (Hebrew: מנחם אורן; 1903, Ruzhany, Russian Empire (now Belarus) – December 1962, Tel Aviv, Israel) was a notable chess master and mathematician.
He played in two Polish championships. In 1926, he tied for 8-9th in Warsaw (1st POL-ch). The event was won by Dawid Przepiórka. In 1927, he tied for 5-7th in Łódź (2nd POL-ch). The event was won by Akiba Rubinstein. In 1928, he represented Poland on fourth board at the 2nd Chess Olympiad in The Hague (+4 –3 =4), and won team bronze medal.
He left Cracow for Rivne, Volhynia (then Poland), in the 1930s. He won in the Rivne City championship in 1938. During World War II, he lived in the Soviet Union. After the war, he returned to Poland in 1945/46, and settled in Lower Silesia.
In 1949, Chwojnik emigrated, via Czechoslovakia and Austria, to Israel, where he had changed name to Menachem Oren. In 1951, he won the Israeli championship and the Tel Aviv City championship. In 1952, he won again the Tel Aviv City championship.
- Gaige, Jeremy (1987), Chess Personalia, A Biobibliography, McFarland, p. 312, ISBN 0-7864-2353-6
- Gaige records the birth city as uncertain, possibly Roznay, and the birth year of 1903 as most probable, but notes that British Chess Magazine, 1963, pp. 74–76, gives 1901 instead.
- Litmanowicz, Władysław & Giżycki, Jerzy, Szachy od A do Z, Wydawnictwo Sport i Turystyka Warszawa, 1986, 1987, ISBN 83-217-2481-7 (1. A-M), ISBN 83-217-2745-X (2. N-Z)
- Szachowe Mistrzostwa Polski - Polish Chess Championships
- Wolsza Tadeusz, Arcymistrzowie, mistrzowie, amatorzy. Słownik biograficzny szachistów polskich, tom 5. Wydawnictwo DiG, Warszawa 2007. ISBN 83-7181-495-X
- OlimpBase :: the encyclopaedia of team chess