Oregon was supposed to be doomed by Chris Boucher’s season-ending knee injury. South Carolina wasn’t supposed to go deep into the tournament, especially after the Gamecocks lost their first game in the SEC tournament, a quarterfinal matchup. So how’d these two programs end up in the Final Four? In the video above, FiveThirtyEight sports editor Chadwick Matlin walks us through their journeys and talks about just how improbable they’ve been.