Through the first round, the Big 12 and Pac-12 are both winless against at-large opponents:
VCU over Oregon State
UConn over Colorado
Wichita State over Arizona
Providence over USC
Butler over Texas Tech
UNI over Texas
Also among those leagues:
SFA over WVU
Yale over Baylor
Hawaii over Cal
Two B1G teams were upset (MSU, Purdue) and the conference did not have any upsets itself
ACC is 6-1 with one upset (Syracuse) and has not been upset yet
A-10 is 2-1 with Dayton being upset and VCU upsetting Oregon State.
AAC is 1-2 with two losses by a combined 4 points. Unless UConn pulls the upset over Kansas, the AAC won't have anyone in the second weekend.
SEC is 2-0 since the First Four with two convincing wins.
VCU over Oregon State
UConn over Colorado
Wichita State over Arizona
Providence over USC
Butler over Texas Tech
UNI over Texas
Also among those leagues:
SFA over WVU
Yale over Baylor
Hawaii over Cal
Two B1G teams were upset (MSU, Purdue) and the conference did not have any upsets itself
ACC is 6-1 with one upset (Syracuse) and has not been upset yet
A-10 is 2-1 with Dayton being upset and VCU upsetting Oregon State.
AAC is 1-2 with two losses by a combined 4 points. Unless UConn pulls the upset over Kansas, the AAC won't have anyone in the second weekend.
SEC is 2-0 since the First Four with two convincing wins.