Having coaching continuity helps, too. Since 1980, Purdue has had 2 basketball coaches - Gene Keady and Matt Painter. And only 4 since 1950.
Right now, there are 7 roster folks with over 400 mins played this year.
Braden Smith: Westfield, IN (Indy suburb); mom and dad are basketball coaches
Fletcher Loyer: Fort Wayne, IN; Dad is a scout for the clippers; mother played volleyball in Lafayette and was an assistant coach at Purdue; Grandfather went to Purdue
Trey Kaufman-Renn: Sellersburg, IN (Louisville suburb); offers from IU, UNC, Louisville
Camden Heide: Minn; Utah private school. Dad went to HS in Lafayette and graduated from Purdue.
Myles Colvin: Indy; Dad is Roosevelt Colvin, who played football for 4 years at Purdue and 10 years in NFL. Sister plays volleyball at Purdue
Caleb Furst: Fort Wayne, IN;
CJ Cox: Lexington, Mass; only had offers from UMass and Ivy Leagues; Painter liked what he saw in AAU games
For what it is worth....
The NBA has 2 former Purdue players right now: Zach Edey and Jaden Ivey. Painter does not recruit many of the 1-and-done types. It could be (1) he's not that interested and (2) they're not that interested in his style. Purdue's worst years under Painter followed a local maximum of success - and a significant number of players graduating. This year has been an exception to prior years, but he's done a much better job at building deeper teams in the past few years.