Nearly every year in the NCAA men's basketball tournament, it seems, there's an unforeseen underdog that finds its way into the Final Four. But it wasn't always like this.

Since the tournament expanded to 64 teams in 1985, teams seeded lower than No. 4 have appeared in the Final Four 23 times, and nearly half of those surprise appearances occurred in the past nine years.

The two charts below show the seeding for each team that made a Final Four since 1985. The seeds worse than four are highlighted, and those teams are listed directly below the chart. From 1985 to 2009, it was rare to have an unexpected Final Four team. Now, it's common.