What Actually Constitutes an "Upset" in Tennis?

Wimbledon 2018 has been highlighted by a litany of "upsets". But how many of these lower ranked players' victories are actually upsets? Joey examines this concept and how to actually gauge the favorite in any given match on today's podcast. Throwback pod where we discussed how to pick a match: https://soundcloud.com/openstanceaudio/how-to-predict-a-tennis-match