 He took third place at Hamburg 1921 ("21st DSB-Congress", Ehrhardt Post won), tied for 3rd–5th at Bad Oeynhausen 1922 ("22nd DSB-Congress", Post won), tied for 11–13th at Berlin 1928 ("BSG", Aron Nimzowitsch won), tied for 5–7th at Berlin 1930 (Karl Helling won), tied for 7–8th in the Berlin-ch 1932 (Helling won), tied for 8–9th at Swinemünde 1932 (Gösta Stoltz won), tied for 6–7th in the Berlin-ch 1933 (Berthold Koch and Kurt Richter won), shared 11th at Bad Aachen 1935 ("3rd" German Championship, Richter won), tied for 3rd–4th at Berlin 1937 ("BSG-B", Carlos Guimard and Ludwig Rellstab won), and tied for 4–7th at Krefeld 1938 (Erich Eliskases and Ludwig Engels won).In 1935, he became "Reichstrainer des Großdeutschen Schachbundes" (Chief Trainer of the German Chess Federation).Schlage, with Alexander Alekhine and Efim Bogoljubow, trained the German national team for 3rd unofficial Chess Olympiad at Munich 1936.