Just wanted to take a moment to post a (barely) semi-OT list of Big Ten schools who have ever plucked a coach from another Power Five school (as currently defined). For simplicity's sake, I only looked back to about 1980 or so, to keep it at least a little bit "modern." Also, this is limited to instances where School A presumably WANTED to keep its former coach and failed to fend off advances from School B, rather than a coach jumping ship because he thought he was about to be fired (like Steve Alford, lol). And it gets murky when you include schools like Butler (my sister graduated from there, love the Dogs!), which didn't have ANYWHERE near the prestige when some of these guys left there that they did after Brad Stevens, plus they have barely been in the Power Five, etc.
ILLINOIS
Brad Underwood from Oklahoma State (2017)
Lon Kruger from Florida (1995)
INDIANA
Tom Crean from Marquette (2008)
Kelvin Sampson from Oklahoma (2006)
IOWA
Todd Lickliter from Butler (2007) ... *Butler was not Power Five at the time
Tom Davis from Stanford (1986)
George Raveling from Washington State (1983)
MARYLAND
Kevin Willard from Seton Hall (2022)
Mark Turgeon from Texas A&M (2011)
Gary Williams from Ohio State (1989)
MICHIGAN
John Beilein from West Virginia (2007)
MICHIGAN STATE
Never
MINNESOTA
Never
NEBRASKA
Barry Collier from Butler (2000) .... *Butler was not Power Five at the time
NORTHWESTERN
Never
OHIO STATE
Chris Holtmann from Butler (2017)
Thad Matta from Xavier (2004) ... *Xavier was not Power Five at the time
Jim O'Brien from Boston College (1997)
Garry Williams from Boston College (1986)
PENN STATE ... *Only became Power Five in 1992
Never
PURDUE
Never (but they've had two coaches during this entire time, lol)
RUTGERS ... *Only became Power Five in 1995
Never
WISCONSIN
Never
All things considered, I would actually say Illinois and Maryland have had the most impressive hires here, considering (A) they both had one very recently and (B) the relatively good basketball tradition at schools like Seton Hall, Oklahoma State, etc.