The one and done thing was not a purely UK thing. That was a Calipari thing and it started his last few years at Memphis.
At Memphis he had 3 one and done players in 8 seasons. Would have had a 4th but that player went pro instead of going to college for a year in 2003. However, 2 of those one and done players came in the last 3 years he was at Memphis. The year that Calipari left for UK, he had 1 one and done player committed, another who has said since that he was going to play for him at Memphis, and another who’s final choice was between UK (with Cal) and Memphis (without Cal). Calipari started recruiting him at Memphis and Paster kept recruiting him when Calipari left. They all followed him to UK in the end. So if he stayed at Memphis he would have had at least 2, but most likely 3, signed for 2009, and 5 or 6 one and done players total in 4 years at Memphis.
The one and done blueprint was created in Memphis, it just had the longest utilization and obviously exploded to bigger heights at UK. UMass was all obviously before his one and done strategy though.