 Prior to unification in 1990, Knaak represented East Germany (otherwise known as the German Democratic Republic) and enjoyed unbridled success in the national championship, taking the title in 1974, 1978, 1982, 1983 and 1984, while finishing a close runner-up in 1975.Throughout the seventies and eighties he rivalled Wolfgang Uhlmann as the nation's best player.In team events, he played on the GDR's Chess Olympiad team at Skopje 1972, Thessaloniki 1988 and Novi Sad 1990.