Ranking Every Manchester United Summer Transfer Window Since 2002

The transfer window system has been a part of English football since the 2002/03 season, limiting every club to just two periods of buying and selling instead of the previous near all-year-round way of doing business. The longer summer window is also particularly important in order to strengthen ahead of a new season, and a bad one can spell disaster. From worst to best, here's a look at every summer window ​United have had in those 17 years. ​Worst: Summer 2013 Ins: Guillermo Varela, Marouane... Via All the latest breaking football news, transfer rumours, analysis, and match reports - 90min http://www.90min.com/