The Yak-9 was the most prolific version of the Yak, and served as the mainstay of the Soviet fighter force during WW2. It was a solid low-altitude performer based on the Yak-7 (a long-range version of the Yak-1). Later models of the Yak-9 fought in Korea. There were over 22 versions of the Yak-9 carrying two different wings, five different engines and seven types of armament...perhaps part of a plot to confuse future capitalist historians.
Cool stuff for Yak lovers: