As recently as 2006 the all-time series between Michigan State and Purdue was tied. Since then the programs have diverged greatly. The Spartans have won three conference titles since then, a Rose Bowl, and made an appearance in the College Football Playoff. Purdue... has made three lower tier bowl games and has technically had five coaches since its last win in the series in 2006 (Danny Hope, Patrick Higgins, Darrell Hazell, Gerad Parker, and Jeff Brohm).
These are two programs that have often been pretty close to each other throughout Big Ten history. Before this recent 7-game win streak for the Spartans Purdue had won sseven of the previous eight.