Bill Foster, who preceded K, deserves more of the credit for the Duke turnaround than he is given by most. In the 3 seasons immediately prior to K's arrival:
1979-80: Reached Elite 8 of NCAA tournament, won the ACC tournament, and had 4 future NBA players on roster. #3 in AP pre-season poll, reached #1, and finished #14.
1978-79: Lost in 2nd round of NCAA tournament as a #2 seed, ACC regular season co-champion, and had 5 future NBA players on roster. #1 in AP pre-season poll, finished #11.
1977-78: Lost in the NCAA championship game (to Kentucky team lead by Jack Givens, who scored 41 points in one of the best performances ever), won ACC tournament, and had 4 future NBA players on roster. #7 in final AP poll.
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K obviously took it to a different level and sustained it for the next two generations, but he didn’t exactly step into a dumpster fire.