After Marco had become a resident of Vienna, he participated actively in the Viennese chess life. Success in chess cafes and clubs increased his reputation so much that he also participated in international tournaments: eg he was in Dresden 1892 Fourth, in Vienna in 1895 first ( his best result ), in Vienna in 1897 of third parties, in Monte Carlo in 1903 fifth in Vienna 1903 third, in Moscow in 1907 and shared second to third parties, in Stockholm in 1912 of third parties.
Marco remisierte each in Vienna two competitions with Carl Schlechter: 1893 ( 0, -0, = 10) and 1894 ( 4, -4, = 3). He won in 1901 in Karlovy Vary against Adolf Albin 6-4 ( 4, -2, = 4). During the Atlantic crossing from the tournament in Cambridge Springs in 1904 returned to Europe, he played on the steamer Pretoria a theme competition ( a rejected King's Gambit ) against David Janowski, he 2:4 ( 2, -4, = 0) lost.
His best historical Elo rating of 2673, he reached in June 1906. At that time he was one of the ten best players in the world.
Marco was because of his very solid play style draw master. Because of his corpulence, he was also called jokingly " large, thick and wide master."
Very well known, he was the chess world but especially as a publicist. He gave tournament books out to the tournaments Vienna in 1903 and 1908, Ostend 1906, Carlsbad 1907, Baden near Vienna in 1914, inter alia, For competition Lasker- Tarrasch 1908 he published a book competition. In 1924 appeared a posthumous collaboration with E. Mazel authored by him book for chess composition: Master of the problem, Vienna 1924, he also wrote himself some chess puzzles. .
Until his death he acted as " secretary " of the Viennese chess clubs. From 1898 to 1914 Marco was also chief editor of the renowned Viennese chess newspaper. In the weekly magazine The interesting journal he edited a chess column.
- Tarrasch - Marco, Dresden 1892