2011 with Oakland
Gio Gonzalez and Robert Gilliam for A.J. Cole, Derek Norris, Tom Milone, and Brad Peacock
In an unlikely turn of events, the four prospects Rizzo traded to Oakland all turned into major leaguers, yet Rizzo still managed to win the trade. Gio has absolutely been as good as advertised with Washington; he posted monster numbers in 2012 when the Nationals took the league by storm, and has remained remarkably steady ever since. No matter how many frustrating moments he might bring, you know Gonzalez will give you a chance to win every five days.
Cole, Norris, Milone, and Peacock have all had their moments in the majors, but none have really stuck anywhere they played. (Oddly enough, both Cole and Norris have found their way back to Washington, although Norris was acquired and then released in the same offseason).
Gonzalez has a 19.8 WAR in six seasons with the Nats, good for 16th in baseball among starters during that time; the four players Rizzo sent to Oakland have combined for a measly 15.6 WAR. None of these players remained in the Athletics’ system past 2014.