Then the 1 seed plays the 16 seed , the 2 seed plays the 15 seed , and so on . No team as a # 16 seed has ever defeated a # 1 seed since the field was expanded to 64 teams , though some have come close . As noted above , despite numerous instances of early-round tournament upsets , no # 1 seed has ever lost in the first round to a # 16 seed .