I think at one point between 1986-2003, the only two first-rounders with 15 career WAR who came up through the Detroit farm system were Travis Fryman and Jeff "Dream" Weaver. Bobby Higginson was a 12th-rounder in 1992. So that's three "league average" guys in almost two decades of terribleness.
Under the craptacular Randy Smith regime, the Tigers went five consecutive years without getting a first-round pick to post a positive WAR in the major leagues, and four of those washed out before they ever made it to Detroit.
The Tigers have had a respectable farm system three times in my lifetime. The first brought **** McAuliffe, Bill Freehan, Willie Horton, Mickey Stanley, Jim Northrup and Mickey Lolich (mainly kids scouted from Michigan and Ohio). The second was the 1974-78 Bill LaJoie group, which included Jack Morris, Dave Rozema, Dan Petry, Lance Parrish, Lou Whitaker, Alan Trammell and Kirk Gibson (along with Mark Fidrych, Jason Thompson, Steve Kemp and Howard Johnson).
I guess No. 3 would include Curtis Granderson and Justin Verlander, but almost all of the "homegrown" Tigers from 2006-15 were picked from other farm systems and developed in-house. They couldn't draft actual players to save their own jobs. Dombrowski just bought a bunch of free agents to try and buy a World Series for Mike Ilitch. It didn't work.
That's what makes Kevin McGonigle so intriguing. The Tigers haven't had a bonafide Trammell-type player come up through the system since I was playing baseball myself. Hopefully Max Clark, Max Anderson, Bryce Rainer and a couple of others will form the core of the next great Detroit era. If not, I'm only 67. I can afford to wait another 40 years.