However, it got me curious, has a team ever swept the major after season awards? As far as I can tell, no team has ever swept the Rookie of the Year, Manager of the Year, Cy Young, and MVP awards. I did find that the following teams did win the Manager of the Year, Cy Young, and MVP Awards in the same year. It's worth noting that Manager of the Year awards began in 1983, so there isn't a lot of history for this to happen.
|1984||Chicago Cubs||Ryne Sandberg||Rick Sutcliffe||Jim Frey|
|1984||Detroit Tigers||Willie Hernandez||Willie Hernandez||Sparky Anderson|
|1986||Boston Red Sox||Roger Clemens||Roger Clemens||John McNamara|
|1988||Los Angeles Dodgers||Kirk Gibson||Orel Hershiser||Tom Lasorda|
|1990||Pittsburgh Pirates||Barry Bonds||Doug Drabek||Jim Leyland|
|1991||Atlanta Braves||Terry Pendleton||Tom Glavine||Bobby Cox|
|1992||Oakland Athletics||Dennis Eckersley||Dennis Eckersley||Tony LaRussa|
|1993||Chicago White Sox||Frank Thomas||Jack McDowell||Gene Lamont|
Interestingly enough, it occurred three times where the pitcher won both the Cy Young and MVP, which makes a sweep much easier.
I also find it interesting that this occurred four years in a row from 1990-1993, but hasn't happened since.
The most obvious change is the introduction of divisional play and a wild card into baseball in 1994. The opportunities for other managers to win manager of the year is just higher. Joe Maddon won NL Manager of the Year this year despite technically having his team place third in the NL Central (albeit with the third best record in baseball).
The attitudes of voters have changed over the years too. Wins and win percentage of pitchers today matters far less. You'd find it hard for Rick Sutcliffe's 1984 performance (16-1 and 3.9 WAR) and Jack McDowell's 1993 performance (22-10, 4.3 WAR) to lead to a Cy Young win today. The relievers Willie Hernandez and Dennis Eckersley would also have a much tougher time today winning an MVP (4.8 WAR & 2.9 WAR in their MVP seasons respectively).