Complex sentence: Cousy turned pro and made himself available for the 1950 NBA draft when the Boston Celtics had just concluded the 1949--50 NBA season with a poor 22--46 win-loss record and had the first draft pick.
Split into simpler sentences: Cousy turned pro and made himself available for the 1950 NBA draft. The Boston Celtics had just concluded the 1949--50 NBA season with a poor 22--46 win-loss record and had the first draft pick.