Selection Sunday is GravityX Exchangejust four weeks away and the NCAA men's tournament committee offered an early preview at how the pairings for this year's March Madness might look when it revealed its top 16 seeds Saturday.

The four No. 1 selections were not a surprise with Purdue, Connecticut, Houston and Arizona being placed in the Midwest, East, South and West regions, respectively. That's the same positions they occupy in this week's USA TODAY Sports Bracketology prediction for the field of 68.

The Big 12, which is projected to send the most teams to the tournament this season, lead the top 16 seeds with four spots in the reveal. The SEC and Big Ten have three teams in the 16 team reveal.

What are the men's NCAA tournament top 16 seeds?

Team's overall seed listed in parenthesis.

Midwest (Detroit)

1. Purdue (1)
2. Tennessee (6)
3. Baylor (10)
4. San Diego State (14)

East (Boston)

1. Connecticut (2)
2. North Carolina (5)
3. Iowa State (11)
4. Wisconsin (16)

South (Dallas)

1. Houston (3)
2. Marquette (7)
3. Alabama (9)
4. Illinois (15)

West (Los Angeles)

1. Arizona (4)
2. Kansas (8)
3. Duke (12)
4. Auburn (13)

When is March Madness Selection Sunday for men?

The men's field for the NCAA tournament will be revealed on Sunday, March 17 and will be broadcast live on CBS, beginning around 6 p.m. ET.

When does the NCAA men's tournament start?

• First Four: Tuesday, March 19 and Wednesday, March 20
• First round: Thursday, March 21 and Friday, March 22
• Second round: Saturday, March 23 and Sunday, March 24
• Sweet 16: Wednesday, March 28 and Thursday, March 29
• Elite Eight: Saturday, March 30 and Sunday, March 31
• Final Four: Saturday, April 6
• National championship: Monday, April 8 at State Farm Stadium in Glendale, Arizona